I have to add another vote for Gentoo. I agree that you just "have less problems" on Gentoo. Updates are from source, but you don't have to update mid-day while working on a project... if you really want the new version of KDE (etc) then start an update and go to sleep, not a big deal. Portage (package management) is amazing, also... for both new and advanced users.
Also, I don't use it for the CFLAGS, etc. If Gentoo were the same speed, or even mildly slower than Ubuntu, I would still use it. The general speed boost is just a bonus. I use very simple (-O2 -pipe) CFLAGS, by the way, but -march-pentium-m on my laptop makes a big difference over -mcpu-i386 distros. -- http://mail.python.org/mailman/listinfo/python-list
