Just started my membership. Guitar is my main instrument. OS has made me happy in a number of ways and I'm very satisfied with my subscription. The Brazilian courses are amazing and everything from Adam and Peter is fantastic. Guided practice sessions are really what I needed in my life. Only reason I won't go 5 stars just yet is that, as a guitar player, I find Peter Sprague's school of thought a little convoluted and odd - haven't been able to get a lot from it. He's a technician, just not my cup of tea. That, and the interface is a little clunky. Overall, huge fan and super appreciative that I got that new years deal on my membership. I've already recommended the service to friends. Thanks a ton OS!!