We used our own 3D engine in our latest project - Gun Disassembly 3D Every 3D model of the gun has from 11 500 to 12500 polygons. Main outer parts are textured. The app performes 20 fps on 1G iPhone/iPod.
I'm not a gun guy, but the app concept is kinda cool. Just wanted to say on your web page link, you may want to re lay it out a bit. I first read the second line as "Up to 60 parts ... (from frame to springs and Requires OS 3.0 or later screws)"
I saw your preview of this game, but since I didn't know much about guns I couldn't help. However, I was (and still am) amazed at your 3D graphics engine and can't wait to see what it can do!