One thing I have found to be true is that inconsistent release is a big problem if using an asymmetrical ball. A little too much behind the ball, or around it, thumb out late. All of these things will make you wish for a symmetrical ball on a bad night...lol. I also agree with Bob in that if you bowl on a wide variety of lanes and lane conditions a smoother, more predictable reaction is always a plus. Just my two cents of course