I have had some stability issues with the Ubuntu 13.04 on my home computer, not on my laptop. It might be related to hard disk encryption (out of curiosity I encrypted my main hard drive in the installer option, resulting in a usable but quite slow system - it's incredible how much the hard drive is still important for performance). I did not have any particular issue on my work laptop with it.
Anyway I gave Fedora 19 a try, with Gnome Shell, even if I am no particular fan of it. So far so good, it seems more stable than my previous Fedora 17 trial, and I get used to Gnome Shell. It's quite different, so it takes a while to get used to, but it is as productive as any other env (maybe more so even).
It made me notice that Ubuntu One cloud storage is much less open that it seems: it's extremely difficult to make it work under Fedora. Some people manage this, I did not. I moved to owncloud, which fits my needs.