GET THE S!
I recieved mine yesterday, I LOVE IT. I have been using a Traxxas system since I started and this is sooooooooo much better. the telemitry is amazing. Very easy to setup and use. If I seriously had to rate this on a scale of 1-10 I would seriously give it a 10. I can't find one thing I don't like about this radio. This is the best bang for your buck and who seriously has 20 cars to race every raceday. If you do I can also see that you can afford 19 other $100 receivers! ok $1900 on recievers alone. YOU WILL LOVE THE S.
If you have a local hobby shop get it from them even if you are paying $20 bucks more. I'd rather support my LHS. Plus think about how much they help you out for free when something breaks and you don't know what. Support your LHS!