RE: Transmitter trays
No I don't use one. I'm more of a "Thumbs Flyer" and the tray just gets in the way. I once tried the tray and I felt very uncomfortable with it. However, I do use a neck strap. I asked a few 3D flyers at my club what they thought about them a few years back, and they thought it was just a fad.
It kind of reminds me of the cigarette girls in the past... don't it?
Pete