I was under the impression that the 6401AALS Caviar Black is a notably better performer than 6400AAKS, and not just due to increased cache. Currently $69.99 at Newegg, free shipping, and actually $5 cheaper than the older model. (I'm definitely not seeing the $59.99 price noted a few days ago, but Newegg bounces around a lot.) Also has a 5 year warranty, vs. the AAKS's 3. Either one is definitely under your imposed price/size ratio and both are very good drives, so if you can find the AAKS significantly cheaper somewhere else, it would in no way be a poor purchase. Personally, I just picked up an AALS.