Well you are right. There is a difference between a Les Paul and any Fender guitar -- I can't really do as much with a Les Paul maybe because it's heavier... Synths though are entirely different, at least as far as the earlier models go...
They all do there own thing. I can't speak with any authority about Synths...not my instrument. I do have a Stylo-Phone though. Its a little monophonic gadjet. Bowie used one on Space Oddity.