Question regarding Well Temp. Tuning

[Richard Moody]

>The big difference I am seeing is
> that after listening to their piano in a well tempered tuning,  the
> heretofore equally tempered musician rarely wants to return to ET.

I wonder what it is that makes the "equally tempered musician" turn away
from ET?.  You say instead of ET they prefer a "well tempered tuning" temp.
How do they know which one?  Hearing just 4 temperaments would be quite a
cost as far as tuning fees go.   What is this "well tempered tuning" that
they prefer?  How did they come to prefer it over all the others?  Can it be
put into cents for machine tuners, or beat rates for aural tuners? If
something other than ET is going to be requested by musicians I hope as a
professional tuner  to be able to provide it.   How can I prepare myself in
case such a request is made?   ---ric