His stroke is fantastic. Some of the secret I think, is that his arm is in constant motion, allowing him to be loose all the time. With a more orthodox swing, there is always the chance that you may tighten up on the match ball or something. One may achieve some of the effect by air stroking in between shots, while standing up, which may be a good idea, if tightening up is a big problem in your game. Just IMO, as always.
I played Bustamante in a tournament. He literally caresses the ball into position. When it comes to style, Bustamante and Efren are the virtuoso's of pool. Their touch and artistry on the pool table is without equal.