From Gentoo Wiki
I have been at the cli since 1981, and started using Gentoo shortly after the initial public release. Despite all the ups and downs of Gentoo over the years. Gentoo is still one of the best Linux flavors, especially for development purposes. Even though I use other Linux flavors, professionally and personally, Gentoo is my primary development OS, and daily general use OS.
There is nothing better than a cluster of Gentoo box's configured for Distcc and Cross Compiling for development work. Despite some of the difficulties due to the evolution process over the years. The amount of control with compiling environments across multiple architectures, is difficult to find any where else.