Can anyone tell me if they have honestly noticed a difference in speed (for general use) between the 5400RPM and 7200RPM 500Gb stock drives? I want to know because I can pick up a new uMBP 2.8GHz today in the store with the 5400RPM drive but would have to wait over a week for the 7200RPM drive 2.8GHz model (they dont stock these). I am travelling for the next month (from tomorrow) and really want to have my MBP with me. Is it worth waiting for the 7200 or should I just swap it out later on if I notice it to be slow? Also, does swapping the drive void the warranty?