Is the most efficient speaker the best speaker?

The interesting thing to with regard to using speakers that offer an amp an easier ride to fixed current, is that it seems to be easier to make such a speaker with a steady low impedance and hence lower efficiency, than it is to do with a speaker with a higher impedance and hence higher efficiency.

Unsound,
High efficiency speakers may(or may not) be more difficult to implement sucessfully, but fortunately there are enough of them available that it`s a viable option for many. They sure work for me.

I'm glad they work for you.

All other things are never equal so its a useless question unfortunately.

More efficient speakers are more efficient and that's about all you can say about that.

Most portable electronics that operate out of necessity on low power are very efficient. DO they all sound good?

case closed.

Touche'!
Some times one can use the basis of "all other things being equal", but I don't think it works at all for loudspeakers, not for the time being anyway.