Well Said Adrian....
And SQ is exactly what Im after.... I Have my Plus/2 and Plus in the same room, 8200^3 open to all sorts of areas... Both of those subs produce... and boy do they produce... but its no where near as clean and tight as I would like it to be, nor is it tuned as low as I would like either. Im sure that I could easily clean it up with a pair of Ultra 13's, but I thought for $3000.00 that I could build something far better. My 2 15" TC-2000's tuned to 14hz (or so) should easily dig down low (roll off around 10hz) and still be cleaner with the build quality of those drivers with the enormous amount of amp power I will be throwing at them... Now granted when its all said and done, I will have invested more then $3K, and the Boxes will each be almost twice the size of a single Ultra, but I have the room... but the finish quality will be Real Wood, and Granite on top...
With both of my drivers and my amps, I have already spent $2K, but I went overboard on the amps. When Im finished with the project, I will probably have about $500.00 more then dual Ultra's would cost me.
In the end, it will be a phenomenal step up in quality, and headroom, but will I ever use that headroom...? I doubt it... Will I embrace the far superior SQ of my Plus's... FO SHO...