I used it for a few months and dropped it a couple of months ago. I noticed an improvement in ball striking, and I figure its because of the weight being consistently on your front side. However, I did lose some distance, and I think its for the same reason that my ball striking improved. I didn't feel the same power from the stack and tilt.
I went back to a traditional swing because the stack and tilt just didn't give me enough incentive to stick with it. I had more trouble working the ball and lost distance(around 6-10 yards with the irons), but I did hit the ball crisper. Just to add, switching back to a traditional swing was actually very easy for me, and I hit the ball just as well. I think the stack and tilt method could be used as a drill to help smother the ball and stay with the shot, make a clean follow through and get on your front side. Thats what it helped me do better!
Hope this helps. Overall I think it could be good for some players and not for others. It helped me out with my traditional swing.