I LOVE this bag. As a compulsive organizer, I hate clutter and this bag is perfect for me. It is not too big - so I don't haul around unneeded junk, but is not too small for my essential items. Keep in mind that "essential" for me includes a snack bag, and a sandwich-sized bag of emergency supplies (matches, bandaids, medicines, etc.). This bag leaves plenty of room.
I have 2 small kids, and am also able to fit their snacks, and a small bag of toys wherever I go.
This bag is BIG on pockets! So many, that I haven't even used them all yet. Very efficient and sneaky pockets here and there that are great for stashing that lone lip balm tube or my gum.
It would fit an iPad really well (if I had one) or a Kindle reader.
No room for my stainless bottle inside, but I just clip it with a carabiner to the side strap and off I go.
Great bag and I highly recommend it!