I too have the exact set-up as "stomper" and I have had the opportunity to fly a couple DA-50s running regular mufflers. Tuned pipe is the way to go for me. It is more power overall and the throttle response is so much better. And it also doesn't sound like you are running a chain saw in the air. I also just finished a Ultra-RC Giles 202 with a Evo 26cc and the CF tuned pipe and a header from Carl Muller. I have spoken to Ultra-RC owner Brian Hughes about this engine on this plane and for those that followed this set-up find this is the perfect combination once the engine is broken in. Tuned pipes work and to me are worth the money. Especially when going to larger gassers.

JP