If you want to 3D with the US60, you'd be better off with the G90 if you want to try a ST. I have a G75 and it's a great motor for sport flying. Properly broken in, these ringed Tigres will practically last forever. The G75 is not the power-to-weight champion of the world, particularly with the hefty stock muffler. I now have a Slimline Pitts, which is several Oz. lighter.

Some people seem to have trouble with certain versions of ST's carbs. Maybe I'm lucky, but mine has impeccable manners - easy to tune, idles and transitions great.