I searched long and hard for the "perfect" bag that's fairly slim and will fit a pro body in the lens-down position. I narrowed it down to this bag and the Lowepro Mini Mag AW but went with this one b/c of the larger interior space. It's great for a day-outing, not something where you'll need your whole kit. It's tall enough to fit a 70-200 f/2.8L IS mounted or a 24-70L mounted with the hood on (NOT reversed). It can fit a 24-70L, 10-22, 50 and speedlight without a problem. In the front pocket I put my cactus flash receivers and trigger along w/extra CF cards and AA batteries. On the back of the bag is a zippered slot that can hold papers or a magazine, i use it to hold some foam "A Better Bounce Cards." I removed the Tamrac logo to make it less conspicuous, it looks great.
I own a Nikon D80 , Nikon SB600 and Tamron 17-50 2.8, And will soon buy a 70-200 2.8 lens. This bag is perfect for putting all those items mentioned. Weather,water proof, lots of pockets including battery, memory cards and even lens cleaning accessories. It even has enough space if you plan to attach a battery pack and a 70-200 lens to your camera without being bulky. Protect your investment, buy this compact, well thought of and durable bag.