I cannot elaborate, as I have never dealt with it, but I'm sure someone will come and say more. I think the button starts to stick after awhile, and there are far less tuning options than Castle's ESCs, but it's waterproof out of the box.
Like I said, I've just heard that many people have had problems, I'm sure there are many more that haven't had a hint of a problem. And Traxxas's customer service is quite good.