Wally,
I am running 2 locally.both RC2. One is a web server with 38 virtual domains point to 31 ibays, and 75+ email accounts. works great. the other is a backup server that I backup data from 9 other servers using rsync on a daily basis. I currently have 3 other RC2 servers in the field in small offices, and they are running like champs. I am not using any groupware at this time, but looking forward to trying it.
Bob