No you don't have to continue to be limited by a 10 channel transmitter... I've got two of them but they are used only when 10 or fewer channels will do. I have been flying the 14MZ for well over a year now, superb locked on range checks, and flawless flight performance.

I have read the threads about problems with the 14MZ and from what I can deduce those problems seem to relate more to user induced issues ... similar to the problems I've read and heard about but never experienced.... with the Spread Spectrum radio.
Lee H. DeMary
AMA 36099