RE: Model Tech CAP 21 ARC
They fly great but are "snappy". Seemed everyone in our club had one in the mid to late 80's. Mine had a Rossi 40 with Pitts muffler.
Like most versions of the CAP 21, it will get into snap/spin situations that will take more altitude to recover from than you have available. Great Planes used to sell similar size CAP 21 kits, perhaps if you are lucky you can find a canopy that will work. Gear should be no problem.
It has been long enough since I had mine that I don't recall where the CG is, or contrl throws used.