PROS: This bag is built very well, and it looks like it should last a very long time. I wanted a bag specifically for under-seat use, and this bag is within the standard restrictions of 12x14x16. It has a loop on the back so that it can be stacked on top of a typical carry on bag with handle. I like that there is a very large open space to pack things into, and it has a nice zip pocket on front for those small things you might want access to easily. I haven't used the bag on a trip yet, so I don't really have any usage comments yet.
CONS: I think the black version is a little dull looking. I think the water bottle pocket on the side is a little small for a diet coke bottle, which is what I'd want to put in there!