ORIGINAL: aeajr
Lots of 3 channel planes can perform rolls and can also sustain inverted flight without ailerons.
Also, many 3 channel plane have ailerons. You don't need 4 channels for ailerons. In fact, if we include gliders, you only need 2 channels, aileron/elevator, which is very popular with slope gliders, some of which are highly aerobatic.
Thanks for the explanation
Off topic, I know, but do you guys think it's worth getting a trainer with or without ailerons? I have flown a 3ch glider a couple of times and wasn't hopeless at flying it, but was a little out of my depth, unaided by the large amount of wind...