I've been through my share of camera bags. I think I own about 8 of them in various sizes. I started out with Lowepro, but I had some issues with their quality and on one of my bags in particular the buckle kept coming loose from the shoulder strap... DANGER!
I now use Tamrac bags exclusively and have 4 of them, from a fairly tiny one that only fits a camera and a flash to a gigantic one that fits all my medium format equipment. The one I now use almost exclusively is the Super Pro 17 (617). The 617 allows me to carry to bodies with lenses attached including my 70-200 f/2.8 L IS. It works great for transporting my cameras to and from my assignments, but once I'm there and using my cameras it just gets in the way.
Boda takes a totally different approach with what they call a lens bag. Designed for shooters who need the ability to change lenses quickly, the Boda Dry and Dry Jr. are flexible and versatile products. While most camera bags are designed for storing your camera and lenses, the Boda dry is designed for active shooting.
The idea is that your arrive at the event with your standard camera case and then put the lenses you need in the Boda. When you need to change lenses you just whip out the new lens and drop the one you no longer need back in the bag. The Boda bag can by worn on your hip or shoulder depending on how you configure it.
The Boda is constructed with weatherproof ballistic nylon and dry zippers. It can hold between 2 and 4 lenses depending on the model and includes pockets for business cards, digital media, a water bottle, a flash and even your wallet and keys.
