I'll probably get one more. Right now I have two regular Microsizers, one 49mhz and one 27mhz. Then the Microsizer Pro is 27mhz, however from what I read the pro controllers don't interfere with the regular ones of the same frequency (must be a different type of modulation).

I tested this out to see and its definitely true the Pro controller will not control a regular non boosted/pro car of the same frequency but I have not tested them both simultaneously to see if there is any interference or signal cancelling.

So anyways the next and last one I will probably buy will be another MS Pro but 49mhz.