Okay... I know this topic has been gone over several times, but I'm still having trouble deciding on which to get in a new 15", 2.8Ghz MBP - 5400/500GB, or 7200rpm/320GB (or 500, really). I'll be using the machine largely for graphic design, but also for various other tasks as my main computer. I've heard the faster drive IS a noticeable difference, but it also drains battery life and runs hot. There doesn't seem to be a consensus on this anywhere. Is the 7200 worth it?