explain why a bit better

README.md

@@ -48,9 +48,10 @@ The concept of "scope guard" was [proposed](http://drdobbs.com/184403758)
 by Andrei Alexandrescu and Petru Marginean and it is well known in the
 C++ community. It has been proposed for standardization (see
 [N4189](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4189.pdf))
-but is still not part of the standard library, as of March 2018. While there
-are several implementations available, I did not find any with all the
-characteristics I aimed for here.
+but is still not part of the standard library, as of March 2018.
+
+While there are several implementations available, I did not find any with all
+the characteristics I aimed for here - safe, tested, documented, public domain, thin wrapping, general, standalone, simple interface... (see feature list below).
 
 ## Features