You'd be surprised how quickly you might want those extra channels. I was flying less than a year and 1/2, and had already went through three radios (one four channel and two six channels) and was wishing for the seventh for mixing purposes. I've since bought the JR 7202 which is a very nice radio for the money. The extra channel comes in very nice when you start mixing stuff together. I would opt for the DX7, but at 100 bucks per receiver, I dont have a grand to replace all of my receivers. JR should have made an option for an RF modulator to plug into it to ease the transition--JMO.
If I were just starting, however, I would go for it. Sure, I'll eventually end up with one--as will most pilots eventually end up with a spread spectrum radio of some brand or another. It would pretty much eliminate stress between us and the FCC.