I've been an apple/mac customer for quite a few years and this is my second macbook pro. I'm carrying it back and forth to school several times a day so it runs the gauntlet as far as traveling is concerned. My questions are- is a simple sleeve enough to protect my computer? Should I purchase a hardcase as well? Also, I typically place my computer on top of the sleeve when I'm using it, to prevent dirt scratches on the bottom and (most importantly) so it doesn't sit in wet mug rings or the like (I use it at coffee shops a lot). Does this inhibit the cooling method of the device? Does it overheat when it's sitting idly (but on) in the sleeve? ANY tips (including recommendations for maintaining the battery power, extending the life and capabilities, etc.) would be GREATLY appreciated. My last macbook ran fine but had some crashes, freezes, and eventually the dvd/cd drive stopped functioning properly after only 2 years. I took it in to Best Buy under my warranty and they ended up replacing it yesterday with this newer, stronger one. Keep in mind, I'm a graphic designer so I'm almost always running huge programs such as Adobe CS5. Many preemptive thanks!