I have the medium sized one (the Rummy) and love it. It goes with me everywhere. As for OP's questions, I'm a big dude (size 40 waist) and the Rummy still seems kinda big sometimes, that said, it conforms to my back very well. I carry a ton of random stuff and it all fits in just the front pockets, leaving the main pocket free for whatever. I've never had issues with the strap digging in either and I have about 10 lbs of stuff in there. Also, fwiw I got the Rummy over the monty because I've got an oversized 17" laptop I wanted to be able to fit.