It depends
I have the slim. It'll hold your PB/iBook, but thats about it. Not even the power charger. Acme has since come out with one with an additional pocket, which will carry much more.
Durability is fine, its not designed to take a beating though.
I have the all black one, and it is very proffesional looking.
I suggest you get one, You can return the bag within one year for a full refund and no questions asked. Thats what they told me anyways.