I fired her up for the first time (parents home, low volume).

The TT was in about the middle of my living room, mouth in the center, not facing any corners, pretty much the worst placement for a sub. I plugged her into the Bash, crossed it over at about 100hz and played "Bass Head" by Bassnectar, my standard bass song for testing any decent system as it has a great drop down low as well as a dynamic bassline.

"Wow" doesn't even begin to describe it. This thing RIPS. It has a subtle, smooth tone but clearly means business, and a sort of airy feel to it while still being authoritative.
And the sensitivity. Let's put it into perspective. At .5 volts, you could hear it in the other room. At 2 volts, the stuff on glass shelves in the entertainment center showcase starts to buzz, and the Bash on top of the TT starts rattling.

Even at full power this NEVER happened with my ported 8". At 3 volts on the TT, my dad was getting a slight headache, but this may be totally irrelevant to the noise, I suffered no effects. Again, this was with the gain on the Bash not up even
one notch!! Just for grins I stuck my head inside the horn mouth, and my hair started standing on end a bit. Neat.
I played some of the deepest obscure dubstep in my arsenal, but nothing could compromise the frequency response of the TT. I heard frequencies I'd never heard before in a loudspeaker, even at EDM concerts and raves and the like. And the cleanliness of this thing is amazing. It was like waking up after a long, blurred dream of port chuffing and high volume distortion. The smooth tone from this TT is just pure bass bliss.
I now see why the braces are mandatory. I never really second guessed it, but for all you second guessers
read and heed. The mouth braces in my TT are not in yet, they will be installed after I paint. At 3 volts, the un-braced mouth panel (Panel 13) was vibrating significantly. Had the whole inside not been properly braced, the sub surely would be vibrating across the floor, even at 3 volts. At 20 volts, I predict the structural integrity of the sub would be severely compromised- as in panels vibrating so much the response is changed, not to mention the whole sub rattling across the floor, sounding horrible. The bracing is not an option, it is mandatory, and this clearly shows why.
War volume listening tests to come once I'm home alone and the neighbors are away.
This project is not officially finished yet, so don't jump ship on this thread just yet! I still must prep the whole sub (sand and stuff), paint the horn mouth red, Duratex the outside, install the mouth braces, and plop it in the corner of my room. Only then will it be finished.