Doesn't the inflexibility of the bag nother you? I had one and after trying it our decided that it was simply a large square bag that keeps its structure even when on your shoulder. In addition, I didn't like the compartment on the bottom when empty.

 
Haven't had an opportunity to lug it around yet.

Looks like it built well i.e. will hold up for awhile. Perhaps will become more pliable after some use. As far as the pocket on the bottom, think its absolutely perfect for a wetsuit and if your not lugging that around stick a couple towels in there or street/casual clothes.

I found the compartment underneath was perfect for t-shirt, sweatshirt and pants for after workouts. The inside pockets are good for gels. I think it's my favorite bag. My daughter has "inherited" quite a few over the past 10 years. It's perfect for smelly shoes in the side compartment and sweaty clothes on the other side. The outside bottle pockets are great and I love the backpack option. Ever try carrying a wheelbag, pushing a bike and carrying a gear bag all at the same time? Heck its good when you are trying to rush your bike and stuff past the hotel's front desk leaving wet tire marks across their tiles.

Yeah, definately impressive.

Was a little worried my TT helmet wouldn't fit, but it did w/o a problem. Like the fact that they even have a strap for your bike pump.

Very rarely I would not have anything to add to a bag.
With this one only thing I could think of would be an outside zippered mesh pocket for race clothes after the race... like you mentioned you could use the other pocket. I haven't tried to fit both running and bike shoes in one, but I think they might fit. Also a thermo pocket somewhere, perhaps inside that could fit an icepack along with a bottle or two for post recovery drinks, but it got enough room inside I could just go buy a cheap one and throw it in there.