The sound alone is a good reason to use 4-strokes, but as you said, you'll get more torque at lower RPM, plus they burn less fuel to do it.

They also don't leave slime all over your plane like a 2-stroke does.

There is a myth that they are more difficult to tune than a 2-stroke, but I have never seen it.

Just use 15% fuel and an OS "F" glow plug. That's about the only thing I can think of that you need to do differently.

Think of it this way: If you're building a dirt bike, use a 2-stroke. If you're building a harley, use a 4-stroke