Below is a review for REI for the Haiku To-Go Shoulder Bag that we use as a Diaper Bag
http://www.rei.com/product/752091
Pros: Good Organization, Good Strap Length, Attractive, Easy Access, Enough Compartments, Great Color, High Quality
Cons: Uncomfortable
Best Uses: Shopping, Office, Traveling, Commuting
Describe Yourself: Practical, Modern, Career
This was the first diaper bag I bought after the Winnie the Pooh one we used when she was a newborn (shower gift from my mom) and I researched for days before deciding this was the perfect one. And luckily, it has turned out to be even better than expected. I love that I can fit diapers, wipe, changing mat, snacks, toys, books, and two sippy cups for her (one milk, one water), and still have separate compartments for my wallet and phone (two big pockets under flap), any important documents like passports (velcro inner pocket, nice and deep), a pacifier and bib and toddler spoon and fork (inside zip pocket), and all of my miscellaneous gear (outside zip pocket) like chapstick, tissues, pens, sanitizer, hair clips, etc.
About the bag not fitting water bottles - you just have to find the right size (reusable) bottles. We have both the Sigg and the Foogo Thermos bottles and they fit perfectly. A previous reviewer said a key clip would be nice - I use a small carbiner on my keys and clip it to the metal rectangular loop that holds the strap to the purse. Other reviewers complained about the rectangular loop turning vertical (which it always does), but that really is more aesthetic rather than functional and it won't wear down the strap over time. Finally, lots of reviewers said they would prefer a magnetic clasp, but I prefer the lock for two reasons: (1) it's a much more secure lock, so if you drop the purse or are traveling in crowds, you feel much more secure about it, and (2) you won't accidentally demagnetize your credit cards by having them too close to that strong magnetic closure (which happened multiple times with a previous bag that I had).
It does get heavy and slightly uncomfortable when it is fully packed (with two full 12oz sippy cups) and full container of snacks and fruit puree squeezes and books, etc, but that's because of the mass I am carrying, not the bag itself.
Overall, I love this bag, have received many, many compliments on it (I have the brown with the green and orange flowers), and have inspired several of my friends to get one too. So durable, wipes clean easily, completely worth the price. And like others said, I love the organization that keeps my stuff separate from my toddler's stuff.