RE: Futaba 4PK quick question
If you are looking for "the best" there is why not also consider Sanwa M11R 2.4 and KO Propo's top offering. Both of these are common among the top racers in the world. Nomadio Sensor is also right up there feature wise.
Or have you done the sensible (and mature) thing and realised that all these transmitters have everything you "need" and opted for a specific brand only because you like the ergonomics (grip and meny system)? The latter was why I went for the transmitter I use today (Futaba 3PK).