I've been using this backpack on my weekday commute for almost a month now and mostly love it. I wish it had an eensy bit more room or was able to expand a little more, but I could also stop bringing everything I own with me. There are three external zippers going to one small pocket, one medium pocket, and the main compartment which has a divider and pad for a laptop (I store a medium-sized text book in mine currently). The small pocket's good for keys, a cellphone and a couple other small items. I store my gigantor wallet, makeup pouch and Kindle in the medium pocket with room to spare, as well as lip gloss and other small items in the 3 mesh compartments and pen/pencils pockets within the medium pocket (oh man, I just found another zipped pocket in there that I hadn't noticed!). In the main compartment I can stash a book, pair of sneakers and gym clothes, umbrella, soft-sided lunch bag, and rain cover for the backpack; there's also a trade paperback-sized mesh pocket I haven't used, and a smaller zip pocket where I put Kleenex/gum/etc. The two external mesh pockets on either side of the bag are perfect for my water bottle and travel coffee mug. I've used the compression strap on the outside for a light jacket, and while I haven't used them yet there are a couple loops presumably for a U-lock.
As far as comfort goes I find this bag to be pretty darn comfy, especially when the contents' weight is centered towards the bottom of the bag. The straps are cushy though they are a bit "scratchy" and make a swooshing sounds when you walk as other reviewers have mentioned (I haven't worn it with a tank top so no discomfort there yet). The chest strap is not positioned awkwardly for me as a lady, though I'm not very large up top. I purchased a medium Osprey rain cover for this backpack and it fits well.