Fly the trainer, fly aerobatic models on the sim, and you'll figure out when you are comfortable enough to upgrade. I went from Trainer to 40 size ultimate bipe, and it was a blast. I still have both the airplanes, and the trainer is mostly in one piece (broke the fuse taxiing back in with gusts up to 35 mph!). I now fly large scale gassers, and while they are fun, sometimes I just get in the trainer mood and I'll go do outrageous things with it. torque roll a trainer, knife edge, inverted spins. Trainers can be damn good fun. Take it easy, but that sim will really tell you whether or not you are ready to move up.