I have owned several of the Royal engines in the .25, the .45 and the .46 size and I can say without a doubt these are by far my favorite engines. They have all had the power and reliability you would expect from top quality engines. I would recommend the Royal to anyone, even over OS. I have owned other brands, OS, Webra, Magnum, TT, Fox and K&B. Some of them have been great, some have been dogs, but the Royals have overall been the best of them. I am currently flying a small Stick with a Royal 25 and the reliability, starting ease, throttle response and top end power are always impressive.

Choice number 2 would be the FX series. And yes, my FX 40 shot the liner a few years ago, but it was replaced free of charge. Don't let anyone tell you the liner problem is just a rumor.