I know one's a 2-stroke & the others a 4-stroke and people say you can't really compare them, but just interested to see what people think the overall best one is.
Aprilia produces 28.6 hp @ 10500 rpm with 19 Nm torque @ 10250 rpm
Yamaha produces 15 hp @ 9000 rpm with 12.2 Nm torque @ 8000 rpm
I think Aprilia would be a lot more fun to ride