I remember reading about a Korean man that sued his wife when the children came out ugly because she had apparently transformed herself to a real beauty with plastic surgery. Jaw surgery alone will probably not make you look good unless you already have good features but if combined with other procedures then it can really transform a person.
I think this is a bit silly anyway, because features can skip a generation or two. I look absolutely nothing like my mother - not in face, figure or colouring
I think surgery (plus the right makeup) can make a significant difference. You can't make ugly beautiful but I think you can go from ugly to OK looking, and from attractive to pretty, and from pretty to beautiful. I did a little filler, a touch of botox, rhinoplasty (post accident but that's a moot point) and chin lipo and honestly...well as Lazlo said in my thread, it took me from about a 5 to about a 7.
Most surgeons do a lot more 'anti aging' surgeries than 'beautification' surgeries. In fact many are actually somewhat reluctant to do anything other than fillers, rhinos and chin implants if it's purely cosmetic and not anti-aging.
Posko, from what I've read it does seem that the 'class 3' facial set up doesn't really show itself until the late teens, especially in guys. I'd be cautious about reducing the chin/lower jaw too much because a) you're a guy and b) it's balancing your nose.