I'm trying to ascertain the difference in the different levels of giant TRX carbon wheels out there. I am specifically interested in the 29 inch versions. I don't see them on the giant website anymore, but the 0 level wheels were twice the price of the 1 level wheels. It didn't give any information at all about the 2 level wheels. My understanding is that the rims are the same, but different spokes and hubs. Anyone have any specifics regarding this? thanks!