Is there any advantage to lower efficiency speakers? 87 or below?

how much live unamplified music is in your listening diet ?
and then with a good mic or two before the tape heads or after ?
try that a bit
but yes we all have our opinions

i think ( and I know the origin of the J Cash comment - seeking to FIRST replicate a live unamplified reference one is VERY familiar with) there are two camps here:

1.) build a full range speaker that comes as close to the reference as possible with manageable efficiency as an outcome. 

or

2.) add efficiency target value into the important parameters list. For all kinds of reasons: small amps tend to be affordable, some customers like hearing damage, the 300 B ...First Watt....fill in the blank)

what i find more interesting is all the in and out of phase junk that gets counted as output.....