Pinza,
Just got back from vacation and saw your post.
Our Xserve/XRAID is a pure joy. Easily the best server at our facility in terms of performance, reliability and features right out of the box. Even our IT guys admit it's the best box in the server room. We have dozens of servers running on everything from NT to XP, AIX, UNIX and LINUX.
The only time we've had to reboot the Xserve is to install software. I continue to do all workgroup admin while IT only has to change tapes in the backup library box since the Xserve is physically in their hands.
The performance is stunning.
The only thing I might recommend would be to get real RAID software. The OS X disk utility only offers 0 or 1, and not both. If you need any other RAID setup (0 and 1) or 3, 4, or 5, you'll need to shell out extra for it -- we were going to, but never got around to it and chose to go with striping for video performance since we have very good backup and can recover quickly if necessary.
Jim
(is Jim)