This bag is perfect for me, it fits all of my gear which includes:
Canon Digital Rebel with battery grip attached, Tamron 28-75, Canon 18-55, Canon 70-200, Canon 420EX flash, Tokina 35-300, filters, remotes, and other assorted small accessories. I attach a tripod to the bottom of the pack straps, which works great. There are nice compartments that pad and seperate all your items and it contains extra outside pockets. Yet with all this, it is small, so you don't feel like you are hauling around a refrigerator on your back.
For the price, you can't really go wrong, unless you have a more than 4 or 5 lenses.