Stuart,
I have and continue to use RTI's with little prob's, RTI makes a high gain antenna if you are having range issues(do not try until ALL else fails, as higher gain means, in this case, more interference) however, you can "daisy-chain" antennas using bnc "T" connenctors, try putting the antennas under the floor or in the attic above/below the seating area(and in different rooms for added control) I have tried this and it works great. As far as Quality control issues, I wont lie, there have been some problems but that seems to be in the past now, not RTI's fault the OEM company for the screen and the buttons screwed up. RTI makes a good product and if hard buttons are a must and RF is mandatory, then this is the way to go, if not then think pronto/ pronto pro. Just remember you get what you pay for.