If you go into Control Panel - Local Security Policy
Under.. hmm. Account and Security I think?
The last 6-7 security policies you can disable and the other set to elevate rights.
That will remove your pops up. I do that standard on Vista computers to remove the annoying pop ups.
As far as resources. yeah, it is a hog. I'm debating that when I install Vista on my home computer if I'm going to just skip installing Aero. Outside that, it shouldn't be too much more of a resource hog.
But, Aero is a big part. I would expect a patch to be out in a few months that will either reduce the resources required or allow you to customize it so its not so draining.
I really believe Aero was targeted more at the work computer than a home user feature though - Those not playing games.
Other than that, I haven't seen any hardware problems. I have some software that won't run on Vista yet but those companies are working on getting a compatible upgrade out.. so I can't hold that against Vista.
As always, wait the standard 6 months to 1 year to move to a new OS in my opinion. Everyone who has switched over already is experiencing all the first time problems.
Those who switched over are the real Beta testers. All those complaints, Microsoft will hopefully take a look at and adjust.
Businesses will switch in 1-3 because of the licensing agreements they get from MS. That way, by the time they switch all us home users who were quick to swtich will have ran into most of the problems.