Hi Ozzy
Running a similar configuration to yours. ME9 XP server, 3/4 users accessing main database. Also about 8 users running remote synchronised databases.
It seems to work well. Access speed is about the same as with ME8. I personally run a local synchronised copy of the database but access the master database for analysis of opportunities etc. and it seems to work pretty well for me.
Never noticed any conflicts. Server also has intranet web server (abyss, perl, php) and email server (FTGate) running.
Paul