I never used Gentoo myself, but I'm hearing every now and then that Gentoo users tend to switch to Ubuntu once their learning curve flattens and the compile cycles become increasingly annoying. "I want to do work with my system, not on my system", some switchers say.
I've been using Kubuntu on my ThinkPad R52 laptop for months now and I'm totally satisfied. There are no complicated or time-consuming procedures to install new software. I just do
apt-get install, and that's it. And from the "universe", "multiverse" and "medibuntu" repositories, I can get all the applications I need.
The same goes for my web servers. With Ubuntu 6.06 LTS, I have everything I need to run web, mail, chat and other services. Thanks to "Long Time Support", I won't have to do an upgrade to a newer distribution version for years.
I've been a SuSE Linux user for many years, but now I guess I could become a Ubuntu Linux user for at least as long. And since I passed the "Learning Linux" phase long ago, I may never be inclined to try Gentoo...