Good idea for a poll AKM.
Plenty of people will have different views.
Equal (or "Flat" is particularly good for MIDI compatibility) - modern music we all hear on radio etc, mostly will be equal temperament these days.
Trying out different historic temperaments, you'll find some major chords sweet - and some minor chords sour.
Some chords in different scales even being sweeter or more sour than other scales.
To me, it's a joy and very inspiring to improvise and compose with one of the pianoforte instruments (like the J. Broadwood), find out something of its history, change the diapason, add the temperament used at the time. (also adding: try out changing the "String tension" to "Full rebuild" and back in the advanced tuning panel - that can set interesting differences in inharmonicity).
The discussions people get into are often about ideas like "Period temperament is not necessary for modern interpretation of past music" and "Equal solved all the problems with tuning".. whereas some who may enjoy period instruments reproducing period music using period relevant temperaments of the time might say "There's something wonderful about experiencing these older pianos using the temperaments of the time" or "I compose using the same technical reasons for sweeter and more sour chords in the narrative structure of my music" and so on. All valid.
But in general, I just argue both outlooks can be valid at the *same* time. One need not be more correct or incorrect than another.
To me, both are valid in their own ways and while I first most loved the old instruments for my music, I did grow to love modern grand pianos too, thanks to Pianoteq.
In the end, the record buying public may hear equal on a grand piano as "normal" and therefore, most will choose it, esp. if the goal is to sell more copies! and it may take someone time to learn to appreciate what the other earlier temperaments brought to the compositions.. but either way, the temperaments are certainly different and can be an acquired taste - but worth the time spent IMO.
All part of the joy of music to me
Pianoteq Studio Bundle (Pro plus all instruments) - Kawai MP11 digital piano - Yamaha HS8 monitors