Thoughts from 6-month-old Gentoo user
I am a six-month-old Gentoo user now! Six month ago, I posted about being a newbie of Gentoo. Now I could say I am happy with my decision of switching from Fedora. Please note that Fedora is a great distribution, I personally think Fedora is better than most of distributions—Ubuntu included.
If you know of Gentoo a little more, you should know that it's a source-based management, you install packages (applications) by compiling source code with Gentoo package management program, Portage. It sounds scary whether if you have experience to tar xf program-x.y.z.tar.gz && cd program* && ./configure && make && make install or not. Of course, you wouldn't have to run the command but just run emerge program to compile and to install it. The Gentoo developers have taken care of that for you.
However, at beginning, the effort of using Portage is not as easy as other binary package management distributions. You need to understand your system more and to configure how you want the package being compiled as you do manually. You need to set up /etc/make.conf, which has C(XX)FLAGS, etc. This leads a common discussion: Does -O3 helps in program execution speed?