I currently have an ASUS G60VX-RBB05 with a GTX 260M GPU (1GB RAM). I'm eyeballing a MacBook 13 or MacBook Pro 15 with the 320M GPU. I'm unable to find a real comparison between the two chipsets. I need to know, would it be a DOWNGRADE to go from the GTX 260M to the 320M as found in both the MacBook and MacBook Pro? Please advise. Thanks!