I mainly fly scale warbirds, and they certainly have their quirks, and things that make them tricky. Especially on the ground.

I keep a couple of different sport planes around to keep me sharp on certain aspects of flight. I have a Kadet Sr. that I oriented as a taildragger. This helps practice the rollout and handling of a WW1 biplane etc, which can be tricky.

Then for just general flying, I have a Sun Fli 5 I am flying. Essentially a Kaos. It is .60 sized and of fairly high performance., A higher stall speed, fully symmetrical airfoil, and retracts. This airplane keeps my depth perception in practice, and really helps on landing approaches and such.

I have found that when I go a season or 2 only flying my scale models, my flying skill drops off. These 2 airplanes have helped me a lot to stay on top of my flying, without having the extra pressure of handling the more complicated models all of the time.