Go 4 channel. I have been flying a couple of years now, so I am out of the trainer phase, but someone gave me a 3 channel trainer that I wanted to try out before selling it to a friend. I took it up last week, and found it nothing like a 4 channel. Once it was in the air it was ok, but not being able to bank without turning or turn without banking made it awkward, especially when landing. This week I stripped off the wing covering and am adding airlerons.