It has been quite a while since I heard the HQD system. That was a very expensive system in its day.
I have heard, much more recently, re-built and heavily modified 57s done by a company called MyEmia. One of these pair of speakers came with an active crossover and was bi-amplified using dedicated EL34 tube amplifiers. The other pair, I cannot remember the specific details, but, I think it was a similar setup. Both pairs were able to deliver music at quite high volume levels and with fairly deep and impactful bass; this is NOT your father's Quads. It was hard to say if they could do all the other things that the 57s are known for because I heard them at two different DC -area Capital Audifests (2015 and 2016) and they were mainly demonstrated at exceedingly high volume levels.