mimoore67,
I would've gone with Spring-Airs or even the Robart Gear that is air up and spring down but for the price $139 I decided to try the ESM retracts. They look pretty good and the machining is well done. I have their gear on a Spitfire and it worked right out of the box. I would suggest talking with Tomas at "VQ-Warbirds" on this question. Everyone seems to have a different opinion but since he sells the ESM gear and the SIERRA gear he can better recommend than any of us.
As to the RCV 1.20, yes it is a great engine and I believe it was the original selection by YT (over in England) when the Spitfire first came out. Keep in mind that 4 blade props for models are at the bad end of efficiency. I tried that route and eventhough I had success, the performance was just not there. They look cool though and in this hobby, each one of us makes unique decisions for our own tastes and circumstances. If you decide to go with a 4 blade, keep us posted on what you think.
Happy Flying!
Loopman
