I have two daws now both running sp2. No problems. Where I did have trouble was connecting a laptop with SP2 onto a wireless network... had to go back to SP1.
sp2 on 3 machines here...2 are used for audio (one does dual role as graphics/3d) and the 3rd is a 'net' box. All work great although I would say that I've done my fair share of tweaking (as I would to ANY O.S.)
My new machine came with service pack 2 installed but it seems OK apart from the problem running oxe install files by double clicking. I've turned off a lot of the features though anyway as they were more to do with internet security and that PC is not and never will be on the net.
Haven't got nor need SP2 on my machines. Installed it on dad's office machine and didn't like it a bit. After installation of SP2, run over your tweaks again. If M$ keeps giving you pop-ups every 2 minutes about the terrible danger your machine is in when you don't have anti-virus or firewall on your offline DAW, disable some service - don't remember which, I don't have SP2 here.
the antivirus popups seem to be confined to the first few minutes of operation then cease. yes, sp2 runs smoothly although i wouldn't recommend upgrading unless you are on the net which is something i don't encourage for a daw anyway.
Yes I am toying with the idea of going online via a macintosh that I use for internet with brickhouse firewall which is pretty tight/secure. So I guess the pc would remain anonamous in that situation.
I'm still with SP1 also, haven't bothered with SP2 since my machine is rock-stable, and the new SP2 features are completely useless to me (don't use the built-in firewall, don't use IE, etc.) It's a networked machine too, I use it for everything (it's behind an OpenBSD box that handles firewall/NAT stuff) and works great.
I agree with symbiote regarding network security - it's much easier (and probably more safe) to run an internet connection through a whatever designed router box.
I use a 40 Euro piece of hardware that even saves me from the connection software of my internet supplier (t-online), with the additional (unexpected) benefit that 'felt' connection speed is almost twice as high
