So far I have not been disasappointed by the quality of HobbyKing's electronics. I have a sensored 6.5T motor+100A sensored ESC - this set (including program card) cost me less than 100 USD! After customs got involved it was like 120USD, which is still one hell of a deal and quite a few drivers seem to use the set in the Dutch/Belgian offroad scene with success!
However, if it's not in stock, don't buy it! I've been waiting for 10 months now on an order that I made for a servo because it's still out of stock!
From what I've heard though service is ok if a little slow, so I should be able to get it as store credit.