I had a pair of Heresy 1.5's. Kind of a transition between the I and II. I stuffed the cabinets to provide a few extra hertz in the bass, upgraded the crossovers, rewired speakers, new binding posts, replaced tweeter diaphragms with Crites, and acoustic foam in the mid horn, which took dome of the "shout" out.
I used a Golden Tube Audio SE 40 with Sonic Cap upgrade and Mundorf oil and paper coupling caps, as well as upgraded binding post and RCA's.
I roll my own cables, both RCA's and Speaker.
Pre-amp was either a Classe Five, Melos SHA 1 or Audible Illsions M3A.
I also used 12 inch stands that tilted back. Although Heresys were built to be on the floor I found that position made the soundstage sound like you were in the third tier balcony of a 1500 seat theater. Not my idea of good sound. If I were to do it all over again I would raise them 15-18 inches off the ground.