@LSUGopher
I have ELX Titans (LCR). Switched from class AB Outlaw 5000 with ~150-175W peak into 8 ohm to 3 channel NCx500. Relatively large room with ~12’ listening distance. Only switched because I needed 3 more channels anyway and I did not want headroom to be a potential issue.
Got the expected extra gain. Sounds great of course. Have not done much critical listening since the install, but other than some reduced hiss close in I would only expect more headroom based on the amp measurement and no other audible change.
As you noted, efficiency of the speakers is relatively low, but they are not very difficult to drive impedance wise.
Haven’t been able to do a full recalibration as I am finishing some construction in an adjacent room and stuff is everywhere so just did pink noise level matching of previous Dirac cal.
My amp is remote mounted in a rack, so can’t help with any of your other questions. Don’t regret my purchase at all.
If you have questions I can answer I’ll keep an eye on the thread.