I have use 3pk and now i use 3pks, and my racing budy use kopropo helios. I'm lefthander and koporopo isn't lefthand swichable, and that is the first thing that i like on 3pk/s, second is wheel adapter sou you can lower weel if you like that, i shure do! From options there a lot on futaba and kopropo - to many if you ask me, but hey it's high end radio and all you need or may need some day is there. Futaba have bigger screen but kopropo have grat weel to surf menu. I'm for futaba but you can't go wrong here, i'ts like bmw, mercedes, porche dilema, and don't forget to check m11 from sanwa(airtronics).
Hope it helps you a bit.
Have fun racing