you don't sound like you know jack either about DD's my friend...and i know your buddy Kurt doesn't either...
I've personally owned just about every single driver DD/Resonance has ever made.
Up from when they were still making the old 9000's, 3500's before there even was an 'a' series...took a knife to quite a few of them as well back in my old spl days.
Remember back when a 3515 was 179 bucks, or 223.20 shipped to your door step? Simply couldn't beat it for the money...until RE came out of the woodworks from the FRC days and i did a drop in and gained 1.5 dB in an install that was made for the 3515's //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif.
I've owned various 9900 series woofers... 2 9915's, 1 9917, even had a 4" coil 9917 that had the prototype 10" spiders...
Ask the gentleman on the DD forum about the old cluster mag woofers, i liked that thing...had a 12...can't remember what the official 'series' number of it was, but it was built around 1998 if memory serves me correctly, it might have been a "limited edition" 9000 series sub, i honestly cant remember the whole story behind it.
I have plenty of experience with them, i learned a lot from having them, what to do, and what not to do, as has Kurt.
Put the "you just don't know" card back in your pocket, because i have had plenty of hands on experience with them.
I worshiped the ground that DD walked on, much like yourself, it was the answer to all questions subwoofers regardless of scenario...if anybody would ask me i would say "Get the DD's, you cant beat them for the money." Which at the time (~99-2000), you couldn't. Then i learned how to do my own thing through trial and error.
They still offer a great product, its tough as hell and very hard to break, the problem is the vast majority of people, including myself can no longer afford the name, if it wasn't for that i'd still be running them to this day.