I have the 250AW and I love it. I've used it in the rain, the snow, and walking around Seattle for several hours. Very comfortable and it doesn't scream photography backpack unless I have my camera out. One thing I really like is that it puts the camera tripod on the side, not the front. There's plenty of room up top and even a slot for a laptop that I don't carry.
My gear is a 430ex II flash, 50mm, 10-20mm, Canon T2i w/ 24-70L attached (hood backwards fits in the main slot, attached does not).
$119 on Amazon toohttp://products.lowepro.com/product/DSLR-Video%20Fastpack%20350%20AW,2283.htm