I've got a M21 in .22 cal, and I've been delighted with its design and performance.
I'll add that the 21 serves its role perfectly for me, and beats the TPH hands down in terms of ergonomics, reliability, accuracy, and price.
I'll bet the Cheetah is even nicer, as far as plinking and pride of ownership go.
I'm curious, though: Does this design use straight blowback and a fixed bbl?
Regards,
--
Brian