I bought the large version of this (13 inch) for my Madewell Transport Tote. I absolutely love it. It fits all my stuff (wallet, Lily Pulizter Calendar, glasses, pens, makeup case, iPad, and my MacBook Air (in its sleeve on its side.) I don't think it's a full 13" long, as there is room to slip my water bottle where it ends and the tote wall. But that's ok! Because that space makes a nice spot to nestle a water bottle without it tipping over.

Without the organizer, things are just a jumble in this tote. Now I can find what I want. The side zip pockets are perfect for storing loose papers until I can get home.

Pros:
Nice size--not too big, not too small.
Has a variety of pockets which makes finding things very easy.
It's got a cut-resistant strap which was the main reason for buying it in the first place.

Cons:
The metal fastening holding the strap to the bag looks industrial, almost like a carabiner for climbing, and not something that would blend well with a dressy outfit.
See the attached picture for this one since it's hard to describe: When the strap is lengthened for cross-body use, its design means there's a small part of the strap on the bottom that awkwardly crosses over and again takes away from a clean looking bag. But, then again, it's part of the safety design so I can't complain too much.