Have tried the AirAura, but not the FM-10. I don't know anyone using one, either. The AirAura can be made to be very clean, but there was something about the high end I just didn't like. I know others who love it, so it's definitely more of a taste than capability thing.
Do you have the FM-10 installed now or are you trying one out?
The AP-2000 had a lot of issues with the crossovers, at least to my ears. Never did like it at all.