diff --git a/docs/CMakeLists.txt b/docs/CMakeLists.txt
index 403cc2af..43df570c 100644
--- a/docs/CMakeLists.txt
+++ b/docs/CMakeLists.txt
@@ -7,4 +7,4 @@ xo_docdir_sphinx_config(
     quantity-reference.rst quantity-class.rst quantity-factoryfunctions.rst quantity-unitvars.rst
     unit-reference.rst unit-concept.rst unit-quantities.rst
 )
-xo_utest_coverage_config2()
+#xo_utest_coverage_config2()
diff --git a/include/xo/unit/quantity2.hpp b/include/xo/unit/quantity2.hpp
deleted file mode 100644
index efd2b75f..00000000
--- a/include/xo/unit/quantity2.hpp
+++ /dev/null
@@ -1,28 +0,0 @@
-/** @file quantity2.hpp
- *
- *  Author: Roland Conybeare
- **/
-
-#pragma once
-
-#include "bpu_array.hpp"
-
-namespace xo {
-    namespace qty {
-        /** @class quantity
-         *  @brief represent a scalar quantity with attached units.  enforce dimensional consistency.
-         *
-         *  Constexpr implementation, can compute units at compile time
-         **/
-        template <typename Repr = double, typename Int = std::int64_t>
-        class quantity2 {
-        public:
-            using repr_type = Repr;
-
-        private:
-        };
-    } /*namespace qty*/
-} /*namespace xo*/
-
-
-/** end quantity2.hpp **/
diff --git a/include/xo/unit/quantity2_old.hpp b/include/xo/unit/quantity2_old.hpp
new file mode 100644
index 00000000..8da5a914
--- /dev/null
+++ b/include/xo/unit/quantity2_old.hpp
@@ -0,0 +1,47 @@
+/** @file quantity.hpp
+ *
+ *  Author: Roland Conybeare
+ **/
+
+#pragma once
+
+#include "bpu_array.hpp"
+
+namespace xo {
+    namespace qty {
+        /** @class quantity
+         *  @brief represent a scalar quantity with attached units.  enforce dimensional consistency.
+         *
+         *  Constexpr implementation, can compute units at compile time
+         **/
+        template <typename Repr = double,
+                  typename Int = std::int64_t,
+                  natural_unit<Int> NaturalUnit>
+        class quantity {
+        public:
+            using repr_type = Repr;
+            using unit_type = natural_unit<int>;
+
+        public:
+            constexpr quantity(Repr scale)
+                : scale_{scale} {}
+
+            constexpr const repr_type & scale() const { return scale_; }
+            constexpr unit_type unit() const { return NaturalUnit; }
+
+            constexpr bool is_dimensionless() const { return s_unit.is_dimensionless(); }
+
+            constexpr quantity unit_qty() { return quantity(1); }
+
+        private:
+            /** @brief unit (established at compile time) for this quantity **/
+            static NaturalUnit s_unit = NaturalUnit;
+
+            /** @brief quantity represents this multiple of unit amount **/
+            Repr scale_ = Repr();
+        };
+    } /*namespace qty*/
+} /*namespace xo*/
+
+
+/** end quantity.hpp **/
diff --git a/include/xo/unit/Quantity.hpp b/include/xo/unit/xquantity.hpp
similarity index 81%
rename from include/xo/unit/Quantity.hpp
rename to include/xo/unit/xquantity.hpp
index fd91528d..3d2606be 100644
--- a/include/xo/unit/Quantity.hpp
+++ b/include/xo/unit/xquantity.hpp
@@ -281,6 +281,26 @@ namespace xo {
             return Quantity::add(x, y);
         }
 
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity>
+        requires quantity2_concept<Quantity>
+        constexpr auto
+        operator+ (const Quantity & x, double y)
+        {
+            return x + Quantity(y, nu::dimensionless);
+        }
+
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity>
+        requires quantity2_concept<Quantity>
+        constexpr auto
+        operator+ (double x, const Quantity & y)
+        {
+            return Quantity(x, nu::dimensionless) + y;
+        }
+
         /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
          **/
         template <typename Quantity, typename Quantity2>
@@ -291,6 +311,56 @@ namespace xo {
             return Quantity::subtract(x, y);
         }
 
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity>
+        requires quantity2_concept<Quantity>
+        constexpr auto
+        operator- (const Quantity & x, double y)
+        {
+            return x - Quantity(y, nu::dimensionless);
+        }
+
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity>
+        requires quantity2_concept<Quantity>
+        constexpr auto
+        operator- (double x, const Quantity & y)
+        {
+            return Quantity(x, nu::dimensionless) - y;
+        }
+
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity, typename Quantity2>
+        requires quantity2_concept<Quantity> && quantity2_concept<Quantity2>
+        constexpr auto
+        operator== (const Quantity & x, const Quantity2 & y)
+        {
+            return (Quantity::compare(x, y) == 0);
+        }
+
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity>
+        requires quantity2_concept<Quantity>
+        constexpr auto
+        operator== (const Quantity & x, double y)
+        {
+            return (x == Quantity(y, nu::dimensionless));
+        }
+
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity>
+        requires quantity2_concept<Quantity>
+        constexpr auto
+        operator== (double x, const Quantity & y)
+        {
+            return (Quantity(x, nu::dimensionless) == y);
+        }
+
         /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
          **/
         template <typename Quantity, typename Quantity2>
@@ -301,6 +371,26 @@ namespace xo {
             return Quantity::compare(x, y);
         }
 
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity, double>
+        requires quantity2_concept<Quantity>
+        constexpr auto
+        operator<=> (const Quantity & x, double y)
+        {
+            return Quantity::compare(x, Quantity(y, nu::dimensionless));
+        }
+
+        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
+         **/
+        template <typename Quantity, double>
+        requires quantity2_concept<Quantity>
+        constexpr auto
+        operator<=> (double x, const Quantity & y)
+        {
+            return Quantity::compare(Quantity(x, nu::dimensionless), y);
+        }
+
         namespace unit {
             constexpr auto nanogram = natural_unit_qty(nu::nanogram);
         }
diff --git a/include/xo/unit/Quantity_iostream.hpp b/include/xo/unit/xquantity_iostream.hpp
similarity index 90%
rename from include/xo/unit/Quantity_iostream.hpp
rename to include/xo/unit/xquantity_iostream.hpp
index 402c77d8..0eb6ce95 100644
--- a/include/xo/unit/Quantity_iostream.hpp
+++ b/include/xo/unit/xquantity_iostream.hpp
@@ -17,10 +17,14 @@ namespace xo {
         operator<< (std::ostream & os,
                     const Quantity<Repr, Int> & x)
         {
+            os << x.scale() << x.abbrev();
+
+#ifdef NOT_USING
             os << "<qty"
                << xtag("scale", x.scale())
                << xtag("unit", x.unit())
                << ">";
+#endif
 
             return os;
         }
diff --git a/utest/CMakeLists.txt b/utest/CMakeLists.txt
index 09cfd8ff..5a063bc0 100644
--- a/utest/CMakeLists.txt
+++ b/utest/CMakeLists.txt
@@ -3,7 +3,7 @@
 set(SELF_EXE utest.unit)
 set(SELF_SRCS
     unit_utest_main.cpp  #mpl_unit.test.cpp
-    Quantity.test.cpp
+    xquantity.test.cpp
     quantity.test.cpp
     bpu.test.cpp
     basis_unit.test.cpp
diff --git a/utest/scaled_unit.test.cpp b/utest/scaled_unit.test.cpp
index d9b1d3d6..74c29918 100644
--- a/utest/scaled_unit.test.cpp
+++ b/utest/scaled_unit.test.cpp
@@ -20,14 +20,14 @@ namespace xo {
         constexpr su64_type su_reciprocal = su.reciprocal();
 
         TEST_CASE("scaled_unit", "[scaled_unit]") {
-            static_assert(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1L), 1)>.natural_unit_ == nu::gram.reciprocal());
-            REQUIRE(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1L), 1)>.natural_unit_ == nu::gram.reciprocal());
+            static_assert(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1LL), 1)>.natural_unit_ == nu::gram.reciprocal());
+            REQUIRE(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1LL), 1)>.natural_unit_ == nu::gram.reciprocal());
 
-            static_assert(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1L), 1)>.outer_scale_factor_ == 1);
-            REQUIRE(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1L), 1)>.outer_scale_factor_ == 1);
+            static_assert(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1LL), 1)>.outer_scale_factor_ == 1);
+            REQUIRE(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1LL), 1)>.outer_scale_factor_ == 1);
 
-            static_assert(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1L), 1)>.outer_scale_sq_ == 1.0);
-            REQUIRE(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1L), 1)>.outer_scale_sq_ == 1.0);
+            static_assert(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1LL), 1)>.outer_scale_sq_ == 1.0);
+            REQUIRE(su_reciprocal<scaled_unit(nu::gram, xo::ratio::ratio(1LL), 1)>.outer_scale_sq_ == 1.0);
         } /*TEST_CASE(scaled_unit)*/
 
         TEST_CASE("su_product", "[scaled_unit]") {
diff --git a/utest/Quantity.test.cpp b/utest/xquantity.test.cpp
similarity index 99%
rename from utest/Quantity.test.cpp
rename to utest/xquantity.test.cpp
index 62a5b3d1..319edcd6 100644
--- a/utest/Quantity.test.cpp
+++ b/utest/xquantity.test.cpp
@@ -1,7 +1,7 @@
 /* @file Quantity.test.cpp */
 
-#include "Quantity.hpp"
-#include "Quantity_iostream.hpp"
+#include "xquantity.hpp"
+#include "xquantity_iostream.hpp"
 #include "xo/randomgen/random_seed.hpp"
 #include "xo/randomgen/xoshiro256.hpp"
 #include "xo/indentlog/scope.hpp"