Phoronix had prepared a second test, now is testing also Fedora 7 to 10 and compare the results with the big U. In my consideration, Fedora became slow in some parts, but there are some results showing big problems with the U like this:
So, if you improve your user-friendly don't means you need better hardware every release.
Testing many version of a same distro can show its evolution. Whatever, I'm happy with my Mandriva 2009.