Preferred Linux Flavor for Web Server?

[Jeremy Fowler]

Also, you don't HAVE to compile everything from scratch during installs.
Gentoo has had Gentoo Reference Platform (GRP) Packages available for
quite some time now. They are a snapshot of prebuilt packages people can
use during install rather than build their own. The only downside is
that the packages aren't maintained and are only created during every
release. Which is about twice a year. So you would have to keep up on
the security issues and build new packages as they come out. However,
you don't have to emerge the entire world. `glsa-check -p affected` from
app-portage/gentoolkit will emerge those packages with known security
holes. 

If you do come across some dependence issues or broken packages, say a
package is linked to a specific library version. `revdep-rebuild -av`,
also from app-portage/gentoolkit, scans all your binaries for missing
libraries, figures out which package the binary belongs, and reemerge
those ebuilds. No more broken packages...
 
I would have to agree that on a slower server, building from source is
less than ideal. However, you can always do it during off-peak hours. If
you kill the emerge process, you can always start it back up where it
left off with the `emerge --resume`. 

Also, you can use ccache, which is a compiler cache utility. 
http://gentoo-wiki.com/Ccache

"It uses the GCC -E switch and a hash to detect when a compilation can
be satisfied from cache. The effect is that packages frequently compile
5-10 times faster than they would otherwise. 

The first time that you emerge a package after setting up ccache, there
will be a very slight increase in its compilation time, but thereafter
(when the compilation is cached), you will notice significant
reductions."

Gentoo "Best Practices"
http://gentoo-wiki.com/HOWTO_Maintain_Gentoo_-_%22Best_Practices%22