a better laptop backpack for little people

My criteria for a good laptop backpack:

• separate compartment for laptop
• large middle compartment with zipper that zips all the way down with gussets is best (pain to open something only half way!)
• exterior height dimension should be about 15"-16" (more and it's way too big. I have a decent laptop backpack from JanSport Insider backpack and it measures 17.5" in height and I'm swimming in it. Since I also have a tiny laptop, this backpack is just WAY too big)
• 12" wide is good
• ideal if there was a water pocket but won't make or break...

Here are the contenders:

First the frontrunner:

Knomo Bathhurst Laptop backpack

16.5"H x 12"W x 5"D

Pros: very attractive (comes in other colors), adultish, interesting zipper compartment, zippers go almost all the way down

Cons: pricey ($159) and may be too small? 

Samsonite Network 2

16.5" H x 12.4"W x 9.4"D

about $70-$100 USD

Pros: nice looking, compact but will definitely hold everything I need, second zipper unzips all the way with gusset

Cons: hard to find...(may order from Amazon.uk and pay for intl. shipping)

Targus 16" Ultralight Backpack (TSB515US)

17.75"H x 12.24"W x 4.5" D

about $30.00

Pros: affordable, attractive enough, slim

Cons: on the tall size and maybe not deep enough?

I bought the DubYao 13" Lightweight laptop backpack hoping it would do, but it doesn't hold enough for me (I think it's because of the 3" depth).

15"H x 11"W x 3"D

$39.99

Pros: affordable, attractive

Cons: just too small, not as comfortable as one would think...

So what do you think? Have a favorite?