I have used it before - but I like DEB based system for the ease of updates/upgrades. I was a Debian user but switching to Ubuntu Server now. I do ike the ease of SME Server though
Just got it installed here on a spare system for evaluation. I'm going to temorarily substitute it for my domain server this weekend to see how it goes.
How do you use it yourself?
Yes, I currently have it installed on 5 customer sites ranging from 3 to 60 users. It just works, no fuss, no reboots every 2 days and supportive and knowledgeable user forums.
The thing that's stopped me using it in a commercial environment is that it doesn't - or didn't used to - support Exchange*, which most (of my) business customers have and use.