I opted for a Bisson Pitts muffler on my .46 powered Rocket. I have since seen a Slimline Pitts that might not have necessitated removing so much of the underside of the cowl. At least, I can remove the cowl without having to take off the muffler. The stock muffler would have required removing quite a bit of the cowl also, and I"m well pleased with the Evo .46, pitts muffler and 11.5x7 APC prop combo with all 3 servos in the tail. Your .61 powered plane should be a screamer.

The gear legs are a bit "springy" which helps soften landings. I bent one on a hard crosswind landing, but simply bent it back and everything's fine. You may find the wheels take on a "toe out" attitude after several flights. Mine have, but cause no problems with ground handling. I will eventually remedy this, though.