I got this for my fiancee and we both like it. We got the large sized one. It's very spacious! We have travelled with this bag and it is pretty secure (haven't worried about anyone trying to open it while we are crammed onto a bus or anything). The laptop sleeve is nice and wide as well. It can hold a laptop, couple books, two water bottles, and a couple small jackets with no room to spare (ha!).
No water bottle holder on the outside. Not too many interior pockets. Probably my biggest criticism of this bag is that the material is super stiff. The shoulder strap has actually scraped my neck a couple times because of how stiff it is. It definitely is not seat-belt soft/bendable.
Good bag for the money. There are little things that I would change about this, but there are also some noteworthy benefits. Overall I'd say it's average. Not awful, not stunning.