I've used it in the store 😀 But seriously, if you are asking about usability, I have aperture running on my 12" PowerBook G4 1.33GHz (which is not supposed to run Aperture at all, I had to modify the info.plist so that I could use it with only 768mb of RAM)
Basically what I'm saying is that it will perform fine provided you have over 1GB of RAM, the better MBP graphics card (256mb 8600GT now I think)
The only problem you might run into is the small screen size/low resolution of the 15" mbp, Aperture was really designed with the 30" display in mind, that is the app itself likes to use a lot of real estate
The 17" with the higher resolution option would be perfect for Aperture!
Sorry for that long response 😱