From what I've heard from otherwise nice Harbeth speakers, if you want to rock out, these are not the best choice in any reasonably sized room regardless of the amp.
Bigger Proacs & ATC's that I've heard are much more capable kicking some butt when desired.
For myself, who also enjoys true dynamics & good quality loud rock music at times as well as rich, accurate sound, I have & really enjoy my highly sensitive Volti Audio Rivals! W/ good tube amplification. They are not hard or bright but big & full bodied, super dynamic, image very well & sound like live music. They will handily out rock just about any speaker you can think of that sounds anywhere near pleasing & non fatiguing.
They are pricey, about $15 - $18K built very well & imo, worth it. They're younger sibling, the Razz (Stereophile class B if that matters to you) is less than half the price & really nice too & will also rock out when desired. I doubt Greg Roberts will do a home audition period but you may be able to see & listen to both of them in an upcoming show. You might really enjoy them.