I have the lowepro 200 AW sport sling backpack(http://www.amazon.com/Photo-Sport-Weather-Camera-Lowepro/dp/B0085TGZ2K ) and I have used it many times both skiing and hiking. It works very well with distributing weight on my back, and it also protects my gear very well. I usually carry it with a 60D attached to a 17-40 and a 70-200 f/2.8 is ii both in the side access camera compartment and with a 50mm and my flashes in the main compartment. The main compartment is also very large and allows you to carry extra clothes, snacks, etc. with you which is great for long days on the mountain. It is very easy to access my gear in the side camera compartment as you do not even need to take the backpack off to access the compartment. The 5diii gripped would most likely not fit in the camera compartment attached to a lens, but like you said, that was not your plan anyhow. My 60D with a grip does fit, but it is snug. If it helps I would trust falling on this thing in the snow fully loaded with my gear, it is a very durable bag, and keeps my gear safe.