I have what I think is an older version of this amp, the HCA-1000. Well maybe not specifically an older version of the amp, possibly an ancestor in some way. It's a John Curl design, for what that's worth- he's, well, let's say he's "colorful."
I bought it used for $200.00 six years ago. For that money, it's a pretty good amp. I use it to drive woofers in bi-amp or tri-amp projects I am fooling around with. It seems really reliable. I've never used it to drive "full range" speakers, just for the low end in systems with MiniDSP crossovers.