After looking around at backpacks for 17" laptops, I went for this one. It's well made and feels quite robust, especially the part that sits against your back. The very well padded 'cocoon' for the laptop takes a Dell M90 (same size as an XPS M1710 and one of the Inspiron 17" models I think?) perfectly - it doesn't flop around inside but isn't a pain to get in/out either. A generous internal flap closes of the laptop section with velcro. The other pockets and holders are not particularly ingenious or well thought out - there's no bespoke section for the laptop power brick for example.
The shoulder straps are comfortable for me (I'm 6'4") and the waist strap can be adjusted to take most of the weight of the fully packed bag (the Dell is a heavy thing to lug around for long periods of time!) so your shoulders won't feel the strain.
This is a large bag. That's the reason I bought it. At a pinch, it will take not only the laptop, it's power brick, mouse, a folder of paperwork and other bits, but also a change of clothes, washbag, pair of shoes etc - enough for an overnight stay. It will just about sneak in below the hand baggage size limits for most airlines.
The other bonus is that it doesn't have 'MUG ME' written across it (read 'Dell' or 'Hewlett Packard' or any other PC makers name). For all the world, it looks like a run-of-the-mill backpack. No-one would know that you're carrying a large laptop, that's for sure - unless they've got one themselves!