Leardriver - I'm flying mine with the ZDZ 50. It is NOT huge overpowering the airframe, as it comes in a bit heavy. Mine, dead stock, is 15 3/4 lbs. with the ZDZ and Bisson muffler. Flight performance is very, very good, and I've tried the ZDZ 40 in similar airframe/weights...the 50 would be my choice (it was).

It is a very solid airplane. Please visit my website, and read about my experience with it so far.