Kodiak, here are some reasons I can think of why he didn't like them.
He made a few comments that suggest they may be too neutral for his system (which includes him). He compared them to the Polks which he perceived had more authority to the bass in the Eminem Killshot song. He also said the sound seems to be generic.
He perhaps enjoys a "colored" speaker as evidenced by the comment "...the lows, mids and highs haven't jumped out at..." him.
Perhaps they have a defect.
Perhaps the amp cannot provide the requisite power down low. It's really impossible to tell from the specs although the stated design, with a linear power supply, should do very well unless there's a design implementation or other defect in the amp.
As for soundstage and imaging, it's hard to tell if they are positioned properly.
The treble being a little bright was very interesting. I can't possibly imagine Axiom spending any more time tweaking the M5 design given everything else it has going on. This is either a listener preference within his room or something is wrong with the M5.
