I think a better approach to this entire thread would have been "buyers beware" Nitro is sellling engines marked as DA , that are not DA . Less drama , more facts .
As far as servace on Chinese engines I am sorry but I have to laught, when you buy a product from the big distributors in the USA that make nothing and import everything , your customer servace is in your price in the way of 5 times the markup. So , in some case when a product is not made by craftsman like DA , and a product is simply imported as is the case in all big 5 USA distributors, I see great customer servace in the price , so noting is free .
Case in point , eflight retracts for $89 , same ones direct $14.00 for set , I will buy multiple ones at that price and take my chances on servace