Well, I have tried an asymmetric mouthpiece and I didn't really like it too much. I didn't like the completely flat rim and the design was too foreign to me. But as far as your question about "cheating" goes, I don't believe there is such a thing. Just play the equipment that works for you. The only way I'll say you'd be cheating is if you put down your real horn and switch to one of these!
EZ-TP - Yamaha Musical Instrument Portal