Steve1981, Spilt milk at this point - but living in Maryland you missed a fun opportunity last month to both hear a bunch of different subs in the recent Gorilla83 meet, and potentially bring your PB13Ultra in for a demo aginst some of the other contenders!
I'm sure Gorilla83 will host another meet -- I strongly recommend you take one in! I'm not of the mindset that you can determine everything you want to know from a basic FR graphs and distortion numbers. They are a big part of the equation yes - but they don't tell everything.
These are my two prime examples:
1) DR-250s in carp's blind speaker meet. When taking all FR charts into perspective the FR graph weren't absurdly different than anything else in attendance, but the speakers sounded utterly
different than anything else there -- as strongly agreed upon by all attendees, whether they liked the difference or not is immaterial for this discussion
2) At the Gorilla83 meet comparing the Submersive HP to the JTR Caps FR graphs one would conclude the Submersives were going to be radically better --- several people in the thread pointed out the same thing. But throughout the auditions you had multiple attendees who liked one or the other better - and the final result of which was better was somewhat split. And not even necessarily long the usual party lines of ported vs. sealed. I actually gave the nod to the triple submersives as best of show over the caps if you discount price differences. But fully believe and saw visual evidence showing the cap pair were more tactile than the submersive hp triple setup -- even with a handicap of a dozen DB in the lowest register where one would think these physical shaking things would be most occurring.
Definately would have need more FR plots at different frequencies, compression tests, more testing of everything to account for these variances in subjective sound quality (speakers) or tactile/felt differences (subs) despite the available measured data to the contrary.