I have compared extensively, many times, Krell Evo-400 vs Parasound JC-1 monoblocks. Outcome emerged to be far from that simple (aircraft carrier vs PT boat ).
To my ears, overall sound picture of both in terms of comparison was closer to, say, Mercedes-Benz (Evo-400) vs Audi (JC-1). Pretty tough battle, indeed... Krell Evo-400 a bit more sofisticated, refined and relaxed, Parasound Halo JC-1 a bit more vivid and sparkling, particularly if mated with JC-2 pre.
Two great pairs of audio design, anyway.
Cannot comment older KSA vs HCA designs..