Based on these impedance curves of speakers over 3 decades, it has to be obvious that these curves are providing exceptional sound to the people grading and buying these speakers. The objective they have set for the speakers are being met. Wilson speakers are very expensive, so, is it reasonable that they expect quality amps to drive them to get the most out of them - either a stereo amp or two mono amps ?
I see two main issues:
1. Adding a woofer planar amp to the Puppy so you can dial in any bass you want is creating a whole different speaker. It is now basically a sub-woofer type situation that is user definable. It is obviously not what Wilson was selling, and is completely changing the sound of the speaker. A more valid comparison would have been to compare his new crossover with the same amp setup.
2. The deterioraton of the old diffracton foam on old Wilson Speakers is a well known issue. Wilson sells new diffraction pads for people to update their speakers. Why not try that first to fix any diffraction issues ? When I bought my W/P 8 used, I knew that updating the diffraction pads was an additional expense that I had to factor in. Did I notice a difference when I added the new Wilson Diffraction pads ? Yes, I think I did. Maybe, I am wrong because I could not A/B the change, but, it would have been nice to measure the before and after using the Wilson recommended method for addressing this issue.
Lastly, I am not sure what to say about the whole "off axis" response issue.