I was running gentoo on my opteron box for a few years, doing updates a couple of times a
week. one thing I really did like about it is that when it ran into an altered config file it
gave you a tool to pick one or the other, or do a diff between them, etc. in many other ways
the etc-update tool needs improvement, but it was very nice in comparison to the issues
I had two times over a couple of years when the updates gave me problems, however when I had a
power hit take out a hard drive I was unable to get a current installer to boot on the system
well enough to get going (this was a week after moving so the availablility of distro boot
CD's was limited). I ended up throwing ubuntu server on there, and so far (through a dozen or
so minor updates and one release update) I've had no problems.
I tend to stick with the releases, although I have several packages that I download and
compile myself instead of useing what the distros provide.