Seeing as almost every other brand of guitar has been dissed ...Actually, I reckon you get the best sustain and vibrato out of a 1999 600cc R6, but only at speeds which are illegal on roads in the UK ...
;-)
Semi-seriously, I have a Yamaha f340, big chiver (on the scale of a Martin D-45) and awkward shape, you need arms like a gorilla to pick at it, if it's hanging from a strap. On the other hand, the tone is good. I have just restrung it with Elixirs (though *not* superfine grade), it now sounds rather more mellow, especially in the mid-range.