My personal opinion is that a person should stick with a trainer until he has reached the point where flying is completely intuitive. In other words, you don't have any problem with the fact that your controls are reversed when the plane is coming at you, you know whether your plane is right side up or upside down, you know exactly what the plane is going to do when you move the stick. The problem with a low wing sport plane is that if you don't know how to do those things, you will have a lot less time to figure out what is going on because everything happens a little bit faster.