Get the extended warranty and still under $600. Very good performance for that price. If possible, OC the GPU to give yourself more performance. Your son should be happy. It can play Crysis and Battlefield. Hurry thou. Don't know how many left.
as far as the asus model in question from microcenter is concerned it had a "dedicated video card" not an "integrated video card" which means improved performance. i think i paid about $700 or so for it but do what you want.