I got this bag primarily for commuting back and forth to work.  I got the small size and it fits my 15 inch macbook pro.  However, this is not a laptop bag, so if that is what you are looking for, this probably isn't for you.  There is a separate sleeve in the back of the main compartment that is really only big enough for papers, or perhaps if you have a small tablet or netbook.  My 15" Macbook fits in the main compartment of the bag.  I can also fit a few other small items: charger, wallet, cell phone, etc.
There are a lot of small pockets in the main compartment for smaller items that I think are really great.  Also, as many others have said the side entry pocket in the front of the bag is awesome.  I use this primarily for my keys or phone.  Its a great way to keep items secure, yet easily accessible.  I do not have to take off the bag to reach these items.  I can just reach around the side.
The cam buckle took some getting used to for me, but after about a month of use, I am finding that I really like it.  Its very convenient for having the preset height for the bag to take it on and off, especially when I am biking.
I've also used this bag for a weekend trip and it worked great as a carry on on the airplane.
Overall, this seems to be very well made bag.  I love the colors and the overall look and design of this bag.