I have SP2 RC2 for a while now.
I have disabled the new firewall features since I have Norton Internet Security.
Aside from that, the SP2 seems to be fine. What I personally like is the new Windows Update Site design.
I've not had any problems with stability of any of my games/programs. This includes SFC EAW and OP.
I really like the new protections in Internet Explorer against downloading things suchs as files and ActiveX programs, however I can see how that would be very confusing for the computer disinclined.
The pop-up blocking is nice too, but I do not use it since I have Norton like I said.
If you feel like peeking in the Advanced tab of the Internet Options, there are some new settings there.
Internet Explorer now alerts you about running downloaded programs (Thier publisher ect, I think too if it is a trusted program, I can't remember), of course, another nice feature, I don't use it, and it can be confusing to those not computer literate.
The Device Manager is also a little different. You'll have to check that out to see. I like that too.
The computer now alerts you for the need of Anti-Virus software, thats wonderful. You'd be suprised how many people still don't have any. Once you install AV software, Windows will see that and stop bugging you about it. Does the same for Firewall if you turn off the Windows Firewall, and have no other.
I leave my computer running for long periods of time, setting it to hibernate autmatically, or sleep. I've noticed that it remains very stable, without freezing or crashing. No blue screens either.
I have been away from the computer for a few weeks now, out of town, and I only just installed SP2 RC2 before I left. Those are only the things I first noticed. So I haven't been around it enough to see much more.
My family has used it since, and they haven't complained about anything yet. So thats nice they can use it, and they are about as computer illiterate as you get.
If I notice or think of anything more, I 'll post it.
-Strat