I dont have any personal experience with Acers, but I have used a couple Asus Notebooks (Z81SP & now the Z96J) and they are rock solid. I have been using the Z81SP for over 13 months and not a problem. Been using the Z96J for 5 months and not a problem either. I dont think you can go wrong with Asus. ;-)
Acer's tend to have pretty bad lifespans, they tend to crash pretty easily too, i have had a couple of acers and i take very good care of my laptops. however, asus seems to be more robust and more reliable than acer in most aspects.
I had an acer, and I wont ever invest in one again, It messed up randomly ( I bought it brand new) in the first two months the battery wont last 20 minutes anymore, the keyboard is funky, it messes up your typing, and the H key doesnt work. My best advice is not to go with Acer. Dell has a video card problem last I heard (and worked on) Hp is probably your best bet.