Maybe I am a sad person, but every time I upgrade from version N to version N+2 on ubuntu, the 50% of the stuff broke (mostly X related stuff). Seems debian upgrades are painless.
But he!.. I am not sysadmin. I even use XP on home to play games :-P. Also, seems upgrading ubuntu from version N to N+1 seems more stable.
I have never been a fan of upgrades. Unlike home users and small shops, most large environments use installation servers, configuration management servers, shared storage, and a bunch of other things that generally make upgrades even more painful than fresh installs.
When your systems look the same, it is easy to get the new (kickstart) image ready, and install systems in batches. You have to do the same amount of work when you upgrade, if not more, since you have to update your configuration files in your configuration management repo, re-test all of your software, and ensure the upgrade was actually sucessful (on each system!).
I know a girl that work on a computer from the GRID, and also use some distro optimized for desktop useage. To me is crazy. But maybe more is to be made with a system you know and love, to with some "better" distro that you don't love and know much less. Also, seems all feedback about debian-ish stuff is ubuntu related. Sysadmins seems much dependants of Google searches (?). And google search has become some sort of "Ubuntu manual", while information about debian stuff is often below a pile of random crap (the "for humans" motto seems to work here, googling for information in google using "Debian" + "error message" always show crazy useless craps from logs and robots, never forums with sane or usable information.
I often don't have to search for any specific distro when I'm searching for stuff. Although part of sysadmin is dealing with distro specific info, it is more usually dealing with applications inside of the distro, like Apache, MySQL, NFS, etc., which are not distro specific.
My point in saying this is that most good sysadmins can switch between distros without issue; the knowledge base is essentially the same.
Back on topic though; doesn't Debian have a hideously long release cycle? One of the reasons I never used Debian for servers was because I didn't want to have to use unstable/testing for everything, and the stable stuff was always too old.
V/r,
Ryan Lane