We have a Windows Server 2003 running. Mostly it works great with around 100 testers. Bevor ACE we have him running 48 hours without any crash.
The most crash came from SD2 scripts or lags from mapping, so I hope in the nearly future the multithreaded maps will solve this problems. The map problems occurs if more then 2 instance on one map is living and working at the same time on a script.
The Server runs with 2GB RAM because its the WebEdition and at this time we havent the chance to change this. Anyway the core is a dualcore.
So we are more happy with win than with linux, because a sceond on running on an ubuntu feisty and often brings many problems with SD2, mobhealth and some other things. Maybe because this one is used more for other things and have to manage 4.3TB on 9 SATA's.