Well trying to add some value ( I hope lol ) in my post .One thing cool about Hobby King vs nitro is that they are slow to manage there reviews under the product. So when they sell something , the first 20 or 30 post are open for all to see .
When they switched from DLE engines to rcg , the reviews were brutal and open , now its difficult to find them.
The one concern I have over engines and you only know this from experience is that accuracy in the machine work is 100% critical to its operation and performance.
When I started in the hobby I bought magnum engines because I was told that they person who started the company was an x os person . Magnum is a great price vs OS . So anyway I struggled my way thru learning to tweek and deal with magnums . One day I tried an OS , well right out of the box , the machine work was flawless vs Magnum and what the motor heads would refer to as "tolerance" .
Well between Saito , OS ect I learned there is a differance and its not just in cost and brand name but in the manufacturig tolerance .yes many will say big deal , I love magnum ect , well its the numbers game and the % that get the good ones vs the guys % of guys dealing with flawless OS engines .
I would have to say the same thing with DA , I have never anything less then preimum when hearing this brand named , so I can assume that the manufacturing tolerance is very very good vs knock offs . so with that I can see why they are concerned that there name is potentially being harmed .

I would also say they need to stop the DA associatiion with there brand and always try to use there full name on everything they make .
trust me , I have lived this first hand lol .
We were selling a USA made candy into mexico , it was a simple 1" egg shaped candy with santa foils . We were copied and the qulaity of the Mexico made product was horrible .
We had to add our brand name printed name on santa beard !!! yep in full !!!