I had a DX6 G2, upgraded to an ix12 after I won one in a club raffle (when that happens, and all of the rest of your stuff is Spektrum already, why WOULDN'T you use it???).
My dad has a DX8 G2, and I sold him my DX6 G2 when I got the ix12, so he could use it for buddy boxing (he's just solo'd for our club and is ready for flying on his own now). We use that because there's so many people at our club that use it and know about it; the only people I know out here in the area that fly FrSky are drone guys, and even then, there are a fair amount that fly Spektrum or use DJI radios (in fact, a LOT of people who fly drones that I've run into are flying DJIs).
Futaba seems to be favored amongst the 3D pilots and the Heli pilots at my field, but honestly? They're all kinda "sticks to stir when you're flying" transmitters in a lot of respects. It gets down to features, ease of use, comfort and feel/ergonomics - this last one is a HUGE HUGE HUGE thing for me; a mini drone that I bought before buying my racing drone had this cheesy little DSMX remote that FELT cheap and tiny in my hands. It's a good thing the batteries only lasted a few minutes, because flying it for anything more than about 3 minutes and my hands felt like they were cramping on the controller. If you plan on flying a bunch of different things with the same radio, make sure it feels good in your hands or else you're going to hate it and wish you'd spent a little more for that comfort.