I used one at a golf shool last year and wish i had one at my disposal whenever i need it. As for buying one they are expensive and it really depends on what you are trying to improve on. One of my swing flaws is that i swing too flat sometimes because i take it back too far on the inside, the explanar gives me the correct feedback on my takeaway and forces me nopt to swing on the inside. Because of the weight of the roller it also acts as a good weight training excercise for golf.