I am using the Futaba 3PKS and it has more features, bells and whistles than I will probably ever use.

If this radio was broke, lost or stolen, I would replace it with the Futaba 4PKS without giving it a second thought. The only difference between the 3PKS and 4PKS is an extra channel on the 4PKS - comes in handy for rock crawling, LEDs, winches, etc.