As usual - I am late to the party as I am a working stiff during the week and don't read ( get sidetracked) by these forums until Friday or the weekend .
Many great comments about speakers on this thread . Especially with a focus on efficient speakers.
My experience - the Monitor audio Platinum ( PL100ii) were very Dynamic and the tweeter was the best . The room was filled with the sound coming from it. The bass was strong . However with 40 tube watts I just could not get them to sound magical at all sound levels. My 3.5 ProAC's, in a different room with 175 SS AMP sound much more musical over the entire spectrum . I posted a thread on AG for help and the few who had helped me convinced me I would need a lot more power to bring them to life. ( you do have 60) I also learned during the process I would only go to floor standers as the footprint as the same.
I had originally replaced Sonus Faber - loved the Silk Dome and Devore gibbon super9's were my choice. John was super helpful and although I did not pull the trigger as a pair of Daedalus Muse Studio were available as a trade with another Agoner. Being value( $$ oriented) I made the trade . I also purchased a Wellborne DRD300 mono's on a whim to swap in for a change of Pace. I am incredibly happy with the Daedalus and they are a piece of furniture/art , much like SF, Devore and others. I also listed to Coincident and they were highly efficient and also sounded incredible. Please take a look and possibly listen to them .
For me ATC 's, like ProAC and Monitor Audio Speakers need more power to sound their best at all times.
Do not overlook the preamp with efficient speakers . It ( higher quality Pre) has made a huge difference for me and the background noises associated with them . I hope you are using Tubes for your pre.
I listen to Jazz, Jazz fusion. Classic Rock - not metal and current rock/singer songwriters 90% of the time . Opera easily puts me to sleep and a few of my friends have pushed me to a little classical . But it is not my normal rotation. all of the highly efficient speakers mentioned in this thread which I have heard, auditioned or owned in this thread sounded wonderful with the appropriate associated equipment. I mention this because the Audio-Note display at the recent CAF was playing hard - metal - rock in the room and I was so blown away with the sound. we were dancing in our chairs. My pre-conceived notion that efficient speakers don't really do it for me with heavy ROCK were erased. I didn't go out and buy my first Metallica album - but appreciated the sound and the music being played.
I have not listened to Zu Speakers for any length of time .
I couldn't bring myself to buy Tektons, not that they don't sound good but I am one that likes a good visual - when I relax and listen to music. I appreciate the craftmanship in the speakers made. when I was younger it was OK to have a wolf in sheep's clothing . As time has gone by the visual experience now matter more to me than they once did.
YMMV
Good look on the search and enjoy the journey. Listen with your ears first!
My latest foray into ATS acoustic panels have also made a bid difference.