My Lowepro Flipside Sport 15L AW, I got very excited when this bag came out. I also have a phototrekker and a vertex. The vertex is great when I need everything, the phototrekker was my first bag, smaller and used as a day pack. I shoot a lot of sports, particularly mountain biking, and skiing/snowboarding. I wanted the photosport, but needed to carry more kit, in particular a 70-200. This bag was on preorder as soon as I found out about it.
Protection wise, all weather cover and then a separate cover othe inside, currently folded back. Everyone who shoots on the mountain has left their bag open once and it gets filled with dirt/snow.
On the sides, 1.5l camelbak bladder (currently in my actual camelbak). Lots of the spots are only accessible via bike/hike/lifts. The other side has my tripod/video head and I can also fit my monopod even with the big head.
Inside is my standard kit:
Canon 1D mkIIn with Sigma 70-200 f2.8 attached
Canon eos 300v w/grip and 40mm f2.8 STM attached (yes it is there!)
Canon 85mm f1.8
1 large pocket with cards/circular polariser/nd filters
I've ridden some pretty gnarly trails with these bag already, if any of you know Whistler Bike Park, Fade to Black and Dwayne Johnson got hit when I almost forgot I was wearing it, and I've no quarms about sending jumps. It is secure and comfortable. Really looking forward to using it this winter, though it isn't big enough to carry back county gear, so will spend most of its life in the slack country!
If any of you guys are from British Columbia, or are travelling up, I'll see you on the hill.