Seeking,
I never heard the Energy Reference Connoisseurs or the RC-50s, but I did hear several versions of the Energy Veritas (the V2.4 and V2.3) floorstanders, which were the top of the line about 5 years ago. They were very wide-range and uncolored, similar in neutrality to the M80s, but a little bit dull through the midrange --- not quite as much detail as the M80s/M60s/M22s-- and much more expensive than the M80s.
If memory serves you can see that mild dip in a Soundstage.com NRC anechoic frequency-response curve for the Veritas. The midrange is down about 3 dB or so compared to the Axiom M80s, and that was quite audible in my auditions of the speakers.
Regards,
Alan
