I've been using a two-year-old Acer exclusively to play RO, with some success.
A couple comments:
Acer gives you a "rescue disk." When Windows dies on you and needs to be reinstalled, they'll tell you to reinstall from the CDs. The CDs of course simply wipe out your hard drive as it came from the laptop factory, so there's only Windows on there, none of your data. This is not reinstallation. I later learned computer manufacturers can get a very small discount (like, maybe 10 bucks) to not distribute installable copies of Windows. This annoyed the living crap out of me.
Also, try to check on the sound card, which of course is built in and not upgradable. I've had more problems with the sound on mine (Realtek) causing incredible lag than anything else. It doesn't happen in every game or situation, but 1.5 fps is kind of a bummer.
I've also had some problems with the Acer hardware getting recognized by other operating systems, such as Linux hard drive rescue boot CD, which couldn't see two different USB drives hooked up. Knoppix, at least for the first year I had this thing, was a complete no-go, locked up solid. If you're only going to be running Windows, though, you should be just fine ... until you have to reinstall. =)