I like both two and four strokes. The small two strokes are a little to pitchy but the big ones with the right muffler sound excellent and more like a full scale aerobatic engine. I have a HP VT49 in a SE5a and it sounds good. The OS 160FX sounds great with a Jtec dual Snuffler muffler in a Extra 300L, very close to full scale sound in a high speed pass.

Multi cylinder four strokes sound great. My OS FT-160 sounds wonderful and running at 5000 rpm sounds like a true Cub engine, so does the sewing machine Saito 90TS.

The Enya VT 240 is insane with a Mejzlik 20X6 prop spinning 9000 rpm, extremely loud. About as close as you can get to V-12 sound!!!!!!!!! I have thought about installing it in a 88" spitfire that was given to me. The plane needs the nose weight but the heads will stick out of the cowl.

Someday I hope to get a OS 3.20 Pegasus and install it in a 1/4 scale Super Chipmunk.