Has laptop pocket.
Somewhat adjustable, can fit most lenses.
Side pockets are convenient.
Fairly durably and attractive.
I've used it several times a week for 3 years and not a single part has broken or even shown much wear.
The main pocket doesn't seal. The cover just velcros over it, but if keep any small items in there, they can fall out. Also exposes your camera and lenses to humidity and potentially rain/dirt.
There is NO WAY to make this thing stand upright when you put it down. The weight distribution of your gear will make it fall forward every time, possibly dumping everything in your loose pockets onto the ground.
Shortage of storage options, the main pocket is the only place that will hold lenses or bodies. A large body (1D, 5Dm2) can basically take up so much of the main pocket that unless you're putting tiny 50mm lenses in there, the body (and attached lens) might be the only thing that will fit. This makes its usefulness very limited. Don't count on having much room for any other large items like speedlights.
The accessory pocket is OK, and has a zipper, but none of the inner pockets seal at all. It has pouches for memory cards, batteries, filters, which are fine. But as soon as you put the bag down, it will tip over and dump everything out of these organized pockets and when you unzip it, everything will be in a big pile. Not cool, especially if you're trying to hold glass filters or something.
I'm sure this is an issue with most messenger bag styles but leaning over will make this thing swing like a big pendulum and crash into stuff, especially if you have a laptop or heavy lenses in there.
I don't recommend the single strap if you carry your laptop and a large body + lenses in here. It will make your shoulder sore quickly. Get a backpack.