Personally, I like the Pro-ATP 10 Pack option a bit better overall. The VO Max 9 Pack does have the shoe pocket, but only has 2 main zippers. I end up putting my shoes in the main compartments of bags anyway (especially since those shoe compartments always take up space from the main compartments, you know what I mean?).
I don't know how many racquets you carry on average, but the bag is big enough for me to carry racquets and gear (change of clothes, shoes, towels, etc.)
Cosmetically, I also prefer the look of the Pro-ATP 10 Pack.
I'm on the lookout to see if Janko Tipseravic is currently or if he is going to be carrying the Monster 15-Pack
What are your biggest concerns and deal breakers for a bag?