I am a big fan of the Trager brand bags. They have a drive for quality and comfort, while offering excellent computer protection.
Here's their website:
http://www.tragerusa.com/catalog_home_body.html
I have had this model for 8+ years. Survived field work, still looks new.
It has a lot of pockets, and the flap over the top comes in handy for a yoga mat or an ultralight sleeping bag.
It doesn't have the "dedicated laptop sleeve" that you seem to be interested in... but their other models do. This one has a well-padded laptop compartment built-in. It does not detatch. I've done a lot of traveling with this bag, and have always had an easy time getting my laptop out quickly for security checkpoints. It doesn't have compression straps, but the top flap you see in the image fulfills a similar role. You can cinch it down to apply an even pressure on the entire surface of the bag (my biggest pet peeve with compression straps is the uneven bulges) and it's just one strap so it's faster to cinch. Now that I look at the other bags you have mentioned in this thread, it looks like you're in the market for something much larger, bulkier. Most of them look like monsters that would surely break my back if I packed them to capacity. This one is sleek and I suppose it must be more of a woman's field pack.