This bag is an absolute bargain!
I bought one for my dell xps 17" and when combined with a sleeve, could not want for more.
I was looking at the likes of the samsonite pillow2 backpack and the Wenger swissgear pegasus. Sure, they are a lot more expensive, but decided to go for this one combined with a quality sleeve for protection of my laptop when carrying to and from uni, home and friends houses.
comfort (4*)-
The shoulder straps are pretty wide and feel like they have been reinforced with a hard flexible plastic, i have pretty broad shoulders and when fully loaded the pack can be pretty weighty, but i haven't had any issues with it digging in and cutting. The actual back support area is quite firm, but not uncomfortable, i presume this is to help with the rigidity of the laptop carrying compartment, so in my books, thats probably a good thing. Personally i would prefer the bag to have waist straps to help distribute the wieght and for added security, but this is just my choice. I can imagine that if the user was a petite female, this bag would be pretty big and potentially uncomfortable, but it is one of the smallest 17" laptop bags around. The styling might make the bag look big and square, but this is due to size and functionality over other things.
Quality (5*)-
the quality of the bag is surprisingly good for ~£20. The actual materials used on the bag are fantistic with quality zips and excellent stitching combined with what appear to be decent materials too, i cant really fault it to be honest. The shoulder straps are pretty good too, although maybe a little more padding would be benneficial. The buckles and pull straps that attatch the shoulder straps to the bag aren't great, they don't feel as strong or secure as some others i have seen, but considering the price point, and the overall quality, i feel this is nit picking. If the bag was £50, then this may be a minor irritation, but at ~£20, i feel that its a tiny point to raise.
Laptop compartment (5*)-
Most 17" laptops are ussually pretty expensive and can be a pain to carry around. This was the reason i was looking at the more expensive end of the market, but threw caution to the wind and purchased this one at less than 1/3 of the price.
Padding is surprisingly good. The actual laptop sleeve in the bag is lined with a velvet type material to prevent scratches, but i would recomend combining with a sleeve anyway for added protection as it doesnt go all the way to the top of the main compartment allowing other things in the main compartment to potentially scratch your laptop, although unlikely. There is about 10-15mm of dense foam padding all around the laptop with a bit more at the sides and bottom edges (something some laptop bags dont have!). The other thing i like about this bag is although it isn't a rigid bag, it is pretty stiff and holds its shape when nothing is in it due to the firm materials and thick, dense padding. This means when your laptop is in it, it is not only secure within, but feels like it is in a safety cell.
As far as dimensions are concerned its pretty good. I have a Dell XPS 17 with a 9 cell battery and it is probably one of the biggest 17" laptops on the market at 42cmx28cmx6cm (at its thickest point). I use a quality sleeve too. If your laptop is bigger than this then i suggest you look elswhere as it is a snug/perfect fit with very little movement in any direction, it holds it still.
Other compartments (5*)-
As my laptop is nearly identical to the size of an A3 pad, i can carry 2 or 3 of these around too, as well as A4 pads, several pencil cases etc etc. With the bag comes a padded pouch for cables. I think this is designed for the power block, but the Dell transformer doesnt fit so i use it for my portable HDD, mouse and graphics tablet accessories. There are other assorted pockets too for bits and bobs and a handy one on the front where i keep a notebook and pen for instant access without rummaging around too much.
Overall i would deffinately recomend this bag!
Style is good and if you are like me (6ft4 male) then it doesn't look too big and rediculous on your back, athough all 17" laptop bags will be similar size.