I have been flying my new Ultimate about a month now. I installed a Saito 180 inverted with the stock muffler, great combination! I built mine per the instructions with the pull pull for rudder and elevator. A little frustrating to install but seem to be working fine, just be sure to check tension periodically. I did not use the kit tailwheel, I installed a DP tailwheel assembly (check DP webtsite). I also used an aftermarket composite main gear after seeing some comments about the kit gear being too springy in rough landings causing wing damage. This is my first biplane and first DP kit, I love flying it and highly recommend it!