Lewm, we should investigate what other gears and the characteristics of the listening room in which Ken Kessler auditioned for that particular review. Do you have any ideas as I couldn't find anything of it yet? Art Dudley seemed to have used one MM (Linn Adikt) without much implications on audible distortions, right?
IMHO, if 324 is mated with EAR tube amp, Audio Note pre amp, or some Class A solid state(e.g. Pass Lab XA series) power amp, its solid state personality won't be any problem at all. This may not be true if it is hooked up with VTL TL-7.5(tube), Siegfried(tube) and Rockport(ring radiator tweetors)...
To me, 324 sounds like a solid state as it really is, but it's NOT thin sounding nor harsh. But be cautious when someone uses certain ceramic or metallic speakers or maybe some high efficient horn speakers in a very "lively & spacious" listening room.
All in all, it was a versatile solid state phono amp which "still" justifies its price tag, and targeted for MM/MI die-hard fans who seem to have no other choices within the same price range.
Best regards
Dan