I bought two complete sets for the Futaba 3PK transmitter about two months ago. I had to install a capacitator for one of my applications (the well know fact that a Nosram Dominator speed control and a Ko Propo digital servo don't work without).

Because I had to install a capacitator I informed Spektrum of the problem and asked what they thought of the problem and where to return them.

I never even got an answer. Thankfully I never returned them either and am still using them. With the capacitator installed not one problem thus far so my conclusion: the product is great, but the service is non existant.

One more story: a friend of mine bought two complete sets and two extra receivers. So in total four receivers. Only two out of four receivers actually worked. So now he has to return them.
I also bought two extra receivers but both of them work fine. They still do have the capacitator solved problem though.

Ciao,
Spiller