Interesting topic here. I have been running the Spek DX4S for a couple years and the only issue I have had was glitch problem with one of my cheaper receivers. That being said I just ordered a Airtronics MT4-S 40th. Anniversary edition, so will see how it compares! I did this mainly for local track support ( I suck at setup,lol...) as it seems 70%+ run Airtronics, its OCRC...