I've had Acer Aspire, running Vista, for a few years and have never had any problems with it. My preference would be Acer but that's not an authoriative opinion, just my experience with one laptop. I also have Acer monitor and originally had a buzz on it so Acer replaced it without issue.
Have you Google'd reviews on either of the machines you mention? That's usually a good place to go to help make your mind up. Also, check out forums for each of the laptops and see what problems might repeatedly arise.