What kind of trainer have you "mastered"? A Firebird Freedom or a Avistar? Some people believe they have "mastered" a plane because they can repeatedly get it in the air and back to the ground where as some people feel it takes more than that. I personally feel I have not mastered any of my planes including my trainer as I am constantly trying to make them do something I have not done yet. I fly everything from a Hanger 9 Arrow to a 1/4 scale Cap 232 gasser. Got a 1/4 scale Cermark Pitts S2B I will be putting in the air soon. So my point is you don't need to master your trainer before picking up another plane but your next plane should be towards whatever goal you have in the Hobby. If your looking at Flat-Outs than I am guessing you want to start practicing 3D flight. I've heard they are good learning tools for it but I've never owned one. I come from the other school of thought that "bigger flies better" and picked up a Ohio Model Products Katana V2 70 for practicing 3D. As stated by OzMo Get some help setting it up if you go for it as small planes will spin like a top and you can loose orientation very quickly. My experience with electrics is that when they go in they almost always land on the most expensive part[:@]