I don't know what you base efficiency off of, but MIUI is pretty solid. Also, if I'm not mistaken, it was in fact MIUI who solved the mystery of the FM radio on the N1, not CM. This is part of why I say they are overrated, because alot people (not necessarily you) seem to think that all hacks begin and end with them. I don't need a history lesson as my first Android device was a G1. Anyway, don't mind me. I'm just the inquisitive type. I have a habit of not just doing things because everyone else has already done them.
All of this may be a moot point anyway, since it was recently brought to my attention that the encryption that Moto used for their current crop of Droids was a TI technology. Nvidiia, to my understanding, does not employ such technology. So who knows...