>UAC.

Only really an issue when setting up the PC. Since then, I hardly see it. UAC is there for a very good reason and it does provide better security, less chance of malware getting in. That said, I'm looking forward to UAC changes in Win7.

>Network speed.

Dunno. Seems fine to me.

>Zip speed.

WinZip works like it always has.

>Speed.

I see a common thread here.

>
>Application incompatibility (due to security changes - not due to OS architecture).

Right. Not Microsoft's fault. They've been telling us for years to run as Standard User. We all just ignored the advice.

>UI changes simply for the sake of changes.

I think some are good, others are eh. But I recall people upset with changes in XP too. Even more changes are coming in Win7.

>Additional hogging of resources over and above what XP hogs (now with less performance).

Are you comparing XP and Vista running on the same hardware?

>
>Just the top of the list.