I'll dip my toes into this one . . .Steve's 8's sounded better that day than I've ever heard 8's sound before, and he seemed thunderstruck by the sound quality as well. We heard them using Audio Note transport, DAC and vinyl rig in conjunction with the M-5 preamp and first my WannaGlows, then the AN Conqueror (300B) amp. They sounded lovely with the 'Glows, but not entirely relaxed on peaks, which changed with the switch up to the 300B amp. It had WE's in it, which didn't hurt any either.
John's speaks weren't exactly Theater 4's, although the drivers were the same, as he did in fact finish his Karlson cabs in time to bring 'em to the meet. The bottom end on those babies is absolutely concussive. Most of the time we heard them with Ryan's 845 amp which was running at 500volts and 3-5 watts. It sounded gorgeous, but couldn't seem to quite reign in the woofers in the Karlson. I don't think John found the sound to be what he expected. Just have to bring 'em back another day! (He cleverly sized the boxes to fit like a glove in the back of his wagon. A real custom fit!)
I hope other guys weigh in! I'm still reluctant to express detailed opinions about these things now that I wear a dealer's hat on the forum. My approach hasn't changed, but the rules have with the status change.
Keep your ears and your mind open.