I had a Byron A-4 for many years, flew it with a Byro-jet and O.S. 91. it had great power. weight was about 12 pounds. in the turns I had to bank quite a bit to get it to come around. it liked to go strait. rolled very fast. take-off was pretty quick but I had to pull it up pretty hard to get it to rotate,then ease off once it was airborne.but then it would clime at a good 45 degree angle! if I got a little to slow on landing it would "dutch roll" or wallow around some. that OS .91 was pretty high strung and I had a few deadsticks with it--not fun, strait and level glide it would really cover ground but if you had to turn it back around it would bleed all the speed and you were landing right there! -- then I converted it to turbine.a pipe from Tam and a Jet cat P-60 and I was an instant jet jock! with the turbine, the empty weight was about 13 pounds and take-off weight was 15 pounds. the power seemed to be about 30% higher all a round. I never had a chance to see how fast it would go because on the third flight the engine quit. and it was still pretty heavy from fuel and it crash landed so hard that it busted it up beyond what I was willing to repair.I learned a hard lesson about turbines,they don't run with air bubbles in the line!