I needed a sander that was capable of fixing uneven surfaces over a large, flat area, and I didn't have the budget for a drum sander or a wide-belt sander.  I had heard horror stories about the difficulty involved in using a belt sander, too... so I was a little apprehensive about buying one.  The philosophy I followed was to buy the best one made, and from all I'd read, that was the Porter Cable 362VS.