RE: Why don't all radios have this feature? Add on if you have one.
Dear Spyder0069:
I have an XP6102 (actualy X2610, which is the same TX but only the non-USA version). My Tx does turn itself off when the battery voltage drops below 8.0V. An audible battery low warning is given when the voltage drops below 8.9V.
Regarding flaps, you do know that you can assign certain swicthes to certain function??? If you used the rocker switch next to the trainer button on the left hands side for flaps, your flaps would be completely propertional. Or you could use the rocker switch on the right hand side. This would give your flaps three positions, like on your Futaba. Don't use the toggle switches at the top of the TX for flaps, unless you only want two-postion flaps, eg flaps down and flaps neutral.
I hope this helps!