Mike60,
I would tend to agree with your assessment.
Lower efficiency often goes in hand with deeper bass extension. The Fletcher-Munson Effect that ALmarg referenced comes into play at lower volumes still which negates that aspect of the design somewhat at lower volume, in lieu of specialized equalization at the lower volume.
Higher efficiency speakers as a whole will probably tend to do all the rest better in general since they will punt somewhat on the bass extension in favor of other things, but there are many exceptions, so it is very hard to generalize effectively.
I would tend to agree with your assessment.
Lower efficiency often goes in hand with deeper bass extension. The Fletcher-Munson Effect that ALmarg referenced comes into play at lower volumes still which negates that aspect of the design somewhat at lower volume, in lieu of specialized equalization at the lower volume.
Higher efficiency speakers as a whole will probably tend to do all the rest better in general since they will punt somewhat on the bass extension in favor of other things, but there are many exceptions, so it is very hard to generalize effectively.