Do you have a Mastercraft trailer? I have an X2 with a Mastercraft trailer, and have never had any problems. On the other hand, I know several people with X2s and X10s that have poorly designed non Mastercraft trailers and ding their props in a heartbeat if they are not careful.
I also know a guy that was loading his Centurion onto his trailer at one of our crappy local ramps, and a chunk of cement from the ramp got sucked up in his prop wash and made a nice ding.
I'm not sure about the answer on the Acme prop? I bought an Acme for my X2, and it's spectacular!