My Asus z70Va notebook currently has a 320gb Western Digital Scorpio Blue drive (PATA). I want to make an external USB drive primarily for backup and restore, using a 2.5 inch enclosure. Given that the internal WD is 5400rpm, would there be any meaningful file-transfer-speed advantage to using a 7200 (with 16mb buffer) in the enclosure as opposed to a 5400 (8mb)? USB 2.0 is my only option, BTW. I'm asking because I already have the new 5400 in hand ready to go into the enclosure, but am wondering whether I should instead return it and buy a 7200. I don't want to bother if there's not much to gain. Thanks.