When I am teaching a new student I loan them my old SIM to use, only a G-2 but it was top of the line once. My instructor loaned me a G-nothing and I did learn quite a bit from it. When I got my G-2 though all I used it for was learning new stunts, it got my brain and fingers working correctly before I did them on a real plane. They can be a big help but nothing is as good as a good instructor.