Can you address any of the issues Mac listed with the lack of gain control?
The wireless hand helds have no gain control, but the receivers do. There's an auto gain scheme that ensures that the transmitter never overloads by automatically gaining down and having the transmitter compensate accordingly (and this works fine and completely transparent as far as I can tell), so as long as you set the output gain on the receiver so that it never clips the output everything is fine.
The belt pack transmitters have gain control.
When using it with new Yamaha consoles as I'm doing (and you say you're planning on) there's still the digital gain control so you have a handle on how hot a signal you want - so I don't see a problem.