When I started using Fedora, it was clearly faster and lighter than ubuntu (which I'd been using since early days). I have to say, re unity and gnome3 - I think both have their pros and cons, but both are very nicely designed, usable DEs. Like +Steven Hale
though, ultimately, KDE won me over for versatility.
Talking about configuration though, that's what I love about a /home partition.... Brand new OS, and 95% of what I was using, including desktop settings, etc, are as and where I left them... 1/2 hour tops and working!
Try that with windows :)