120AX is easier to maintain and uses less fuel. FZ110s has insane amounts of torque and sounds really cool.

I love thermodynamics and once I saw/read how the YS uses the chamber under the piston to compress air and feed it into the combustion chamber, along with pressurized fuel, I had to have one. Sorry I can't find a link right now.

Nice thing about electrics is (generally speaking) they work or they don't - no tuning, just plug in and fly away, and you basically get the same performance day in and day out given good battery packs.