I have used one. It is certainly quite interesting and if used enough will do wonders for your swing plane but what I found was that it should be more suited to the individual rather than creating a generic swing that might not work for everyone (that's not to say it didn't work for me though- I just felt that some might not like it). Overall they are pretty useful though. You certainly won't get any instant results from using one although they are excellent for providing a sense of feel that a complete novice can then copy although I doubt you fall into this category so you would have to work with one for a while. I know people who have been raised though their golfing life using one and they do have pretty spot on swings- but I don't understand how this is the case yet they are not great players. Why do you ask- have you not used one before and are therefore thinking of trying one out?