Anyone seriously interested in very high efficiency speakers, I would encourage to invest in a modest box modeling program. I see a lot of claims made by manufacturers for bass extension and efficiency that are physically not possible in the size box they are using, unless they make some very optimistic assumptions about boundary reinforcement and/or the contribution of the reverberant field. If you don't believe me, look at Stereophile's measurements of speakers that claim efficiency in the mid-90's or above. Very few come close to delivering on their claims.
Eminence Designer is $79 from Parts Express, and would allow you to make educated evaluations of the claims manufacturers make. This is an easy-to-use and powerful tool, and after a while your own internal "BS detector" will be calibrated well enough that you can just look at a claim and know whether or not it's overly optimistic.
At the very least, something like this would allow you to make valid apples-to-apples comparisons between manufacturers who measure with different yardsticks.
Duke
dealer/manufacturer
