I'm one of only a couple of us at my club who uses a tray. The big reason I use one is that when I fly on my sim I'm sitting down at the computer and use both my thumbs and forefingers. This is the way I'm comfortable. I use this tray
http://shop.rcamodels.com/High-Wing-...ping-HWT-1.htm which lets me keep my hands high enough to fly like I do on the sim. The company makes four different models. I'm very happy with doing business with them as they make quality products and have good shipping times.
Tom