Most everyone I know learned to fly on regular full house balsa trainers .35 to .60 size be it the ones you had to build in the olden days or the later arfs of the same trainers. Some like me learned without instructors others learned with and some with buddy boxes. Just about every one of us had no problem moving to a mid wing or low wing .40 to .60 size airframe after mastering the trainer. Second planes were often Cubs and the different variants, Spacewalkers, Four Stars etc. By the time the third and fourth airframe came along it was not unusual to see them flying much more advanced airframes .60 size or larger.

Most of the people I see learning on these smallish foam airframes tend to stay with them for a much longer period of time. Many never venture beyond. When they do they are aghast that they can’t peg them off the runway or cartwheel them on takeoff without causing a fair amount of damage.

Generally I find the better pilots learn flying on old school balsa trainers that are 60 inches span wise or better and using full house controls without any aids. If you watch someone learning on these old school airframes the care, control and attention seem to be the main focus. Guys with the foamies will take more chances, pay less attention to detail and accept poor flight practices as a form of entertainment just because they can bounce the things off the ground with little or no damage.

My preference is old school balsa trainers in the 60 plus wingspan be it electric or fuel powered. My all time favorite is the Telemaster .40 with a Saito .56 with flaps. Started out as a trike then converted it to a tail dragger and finally put it on floats and skis. I even put a cradle on the top of the wing and took up 3 meter sailplanes and released them via a 6th channel.

I have an electric Telemaster .40 size
Avistar .40 Arf converted to electric.
PT 60 with OS .61
Early Telemaster 66
Sig Kadet
Lazy Ace
All with flat bottom airfoils and differing dihedral and they all can perform basic aerobatics well enough for any beginner to get a fair handle on what is needed to perform them.

Better yet is for an instructor to use a buddy box at a great enough altitude and teach the student to recover from unexpected upsets.

Dennis