There is an enormous amount of room for everything imaginable. 15" laptops fit in the padded section with no problems. The quick outer zipper makes retrieving your laptop for inspection or on the plane painless & easy! I have yet to cram enough stuff in this bad boy to need the expansion, and judging by how heavy I've had it, I don't want to! (I'm sure it could take the weight tho!) The strap, though fixed, is incredibly easy to adjust. The fabric seems quite tough and likely to last for some time, along with looking sweet! The various pockets all over the place make being organized easy, and annoys TSA inspectors. (jk)
My biggest complaint is that the shoulder pad could be a little more...well padded.
That said, it's still a great bag, so buy it now!