Where are you running 4wd off-road carpet at, banana?

I'd grab whatever feels comfortable in your hand. I like the lynx 4s from hitec but I've used sanwa and futaba in the past as well and they are all great radios. Check out Indy RC World, they usually have several high end radios in stock you can try out and see how you like them. I think the 4px always sells out quickly there but either way, someone there will have one you can hold and get a feel for at least.