You get what you pay for. YS is a high performance engine, and it will blow away both OS and RCV. However, just like a Ferrari, it's not for everybody. BTW, I'm using YS four stroke in almost all of my warbirds.

Check out my website to see and hear the spectacular performance from YS engines: [link]http://www.warbirdobsession.com/[/link]
Especially check out the Kyosho Zero and the Dymond Bearcat, both of which are similar in size and weight to your plane.