Forgive me if my answer is overly simplistic and lacking a few details, but of the 15.4" screen models you listed (the 1501, 1505, & 6400), the 6400 that is shown in this thread will beat any of the others at the current $699 price point. I would consider the 640m a different beast altogether. It has a smaller 14.1" screen and claims to be "sleek & stylish". For the style points, you do lose some power & features compared to the 6400 (the DVD burner, a better video card, 40GB of hard drive space, & 512MB of RAM immediately jump out at me). However, unless you plan to use these features they wouldn't be important to you, anyway. If I were you, I'd decide between the 6400 and 640m. Or you could wait for the always inevitable better deal to come along. Good luck, CK