I purchased the dunlop backpack also. It is essentially a small, generic backpack with dunlop logos and colors slapped on. It looks nice, but it lacks any tennis specific features.
For example, it has two compartments. The back compartment for the rackets does not have any features to secure the rackets, such as a small velcro clip or loop.
The racket compartment has a pocket with a zipper, but it's not very useful: anything you put in that section will irritate your back since it will jut out from the back of the lightly padded back. Also, the zipper for the compartment could scratch the finish of your rackets.
The front storage compartment again, does not have any tennis specific features. It has a section for storing small cards (why would anyone store them inside the pack instead of a wallet?), a small pocket for a wallet or cell phone, and some spots to place a few pencils or pens.
There are two outer pockets for water bottles or a can of balls.
The backpack is not very well thought out for tennis purposes, and at $50 retail, is not a great value.
The stitching of the liner was defective, and uneven throughout.
It's basically a cheaply made backpack. Aside from the esthetics, fairly disappointing.
Overall grade: C
edit: feel free to buy any normal backpack with two compartments and a double zipper for the rear compartment. It will work just as well, and run you a third of the price...