This is a very compact backpack and I'm highly pleased with it for the price (I paid £25 on Amazon).
It functions perfectly as a daypack for sightseeing: padded compartment for a smallish SLR camera, guidebook or two, Kindle in the outside pocket and plus space for various other small odds and ends (eg extra lens) or even a light jumper.
It can be a bit small for to and froing for work, but I deliberately chose a smaller pack as I had found I had been carrying too much stuff.
My wide screen 15.6 inch computer only just fits in the pouch, and things get very tight indeed if i then want to take my camera. However I have recently bought a 12 inch netbook and this, plus camera and Kindle and small odds and ends fit perfectly guaranteeing I'll be using this combination next time I need to travel for work.
Minor disadvantages: only colour is black and it falls over when put on the ground (it has a sloped base)