I made a twin Kadet w/ a 20% airfoil. It didn't have ballooning tendancies like the flt bottomed one. I can't say if it flew any better., but it was different.

My mods to the standard Kadet are the same as the others....
Ailerons and flapps, hinged at the TE spar. 1/2 dihedrial. Flaps not needed at all, but add to the fun factor. I can dive at the field and about 2 foot from the ground, and w/ full flap and partial elevator enter a loop. At the top give more elevator so it exits a bit higher than it entered, but go right into a landing.... Sure does give the illusion it's gonna crash It woudl easily do rolling circles at half throttle. Mine was a trike gear, and it was a blast to do one wheel touch and goes. I also added a fixed tailwheel as I found I was scrapign the wood on the tail as it is so easy to land scraping the tail.
Mine is/was powered by a K&B .65 swinging a 14x6 prop. Not too much speed ( which you don't want in a Kadet), but tons of torque. Also have a Bomb door ( which also makes a good speed brake), and an external release for stuff that won't fit into the bomb bay. Mine is over 10 years old, and doesn't have any flying wires, or extra bracing in the fuse. I actually retired it last year as the Monocote was always shattering, and now the fuse is rather fuel soaked. I'm all elctric now, so I'll probably build a new one this winter and electrify it. May go with the 20% airfoil on it Also sold the Twin Kadet as the motor pods are too close to run the larger props needed for electric power.

One thing for sure.... Nothign flies like a Kadet.