LOL Like I said I have the same one (I think anyay from what I can tell from this pic) For me is was just too big and didn't fit my bike very well due to the fact that I don't have a lot of post exposed and my seat is a little bit forward. If that is the same Topeak bag I have it has a hard mount to the seat that you have to bolt on with alen keys and my saddle flexes in the back so this also stopped the saddle from being able to flex. It is WAY bigger than it looked like on the web too. LOL I got it for Christmas and have put it on my commuter where it works fine. One thing it does have going for it is that it will hold a ton of stuff.

You know now that I got to the Topeak web site (which bugs me a bit too) maybe it isn't the same bag and I should have kept my mouth shut. Here is the bag I got (the Med version). I really liked the idea of the pump holder under the bag since I have a Crank Bros pump that I carry in a jersey pocket but it doesn't work all that well. I really struck out on this bag, thus my hatred for it. LOL