I have used a pair of JC-1s for a year or so now. fine amps IMO. I run them in normal bias most of the year. High bias in the winter. They can drive my 20.7s with ease. I don't know what I'd replace them with at anything less than twice the price.
For some reason or another they do seem to require an extended period for break-in and in.
They have been around for so long now there is a lot of contradictory info about them all over the web.
I did an extensive at-home comparison between them and Cary SA 500.1. I preferred the JC-1s....which surprised me. I'd recommend having a listen. Operationally they are absolutely bullet proof.
No experience with JC-2
Good luck!