Lowe Pro Classified bag advice

I am thinking about getting a LowePro Classified bag but I wonder if messenger-bag style bags can really wear down your shoulder/back. I plan on carrying a t3i + 17-55 2.8 + 70-200 2.8 as well as a laptop now and then along with flash and plenty of batteries.

Does anyone have experience with these bags? I like to go hiking a lot and I imagine this will be ill-suited for such adventures (but no problem in just going tour-ist style and hang it around the neck).

Thanks yall,

Scott