From what I've been reading, some people really can't understand the difference!
I've taken a few lessons from a few different pro's! The greatest lessons I've gotten were from Joe Tucker. But at the same time, a 2hr lesson from Funky where he gave me only one thing to work on was probably the most helpful to my game where I saw an improvement in less than a month!
How much of an improvement you ask?? I was getting 3 on the wire to 9 in 9 ball! A month later, I was giving them a game
I spent 200 on that lesson and I wasn't that satisfied for a couple days but I said I would do what he said! 3 months later,,,, I made a few g's from that lesson. And to this day I still consider that one thing to be the greatest lesson I ever took!
What's my point?? Don't ever underestimate what a great player will tell you AND don't underestimate what a quality instructor can help you with! It takes dedication!