Kev, my opinion for what its worth

Power- A two stroke of the same displacement will deliver more power, and weigh less

Fuel Consumption - The four stroke uses way less fuel than the two stroke- A side benifit of this is less Goo on the airplane. Way less

Noise Level - the four stroke is quiter and has a much nicer sound

Ease of Use - Not much difference. Once you set the carb up correctly, just use it, same for both 2 and 4 strokes. The four stroke will require a valve adjustment once a year, depending on use. No big deal.

Quality - Again, not much difference overall.

Myself, I'm converting to four strokes where I can. I just like the cleaner burning and the sound.

Don