Optimizing TNT, Triplanar, Transfiguration Temper

I'm writing because of a combination of frustration and potential in my turntable set-up. I have never gotten the sound from the system that I expected, but feel that I am beginning to glimpse the potential of achieving it. I have made some changes recently that have led to more changes that have brought me closer to what I have heard from other systems with similar components. I am hoping someone can guide me toward finally obtaining the basic qualities that I'm looking for and I can fine-tune from there.
What I have heard before from lesser components and am not getting is the sound of the transients jumping off the record. I thought this problem was merely from the characteristics of the Transfiguration Temper Supreme, but with some modifications of the table I am beginning to hear it and wanted to see if I could bring it out further.
Let me back-track and tell you my components and what modifications I have made so far. I am running a VPI TNT upgraded to 4 (w/ the rectangle cutout for the motor), with the original motor and just added an SDS (which made the biggest improvement), a Wheaton Triplanar tonearm upgraded to VI, and a Transfiguration Temper Supreme cartridge.
When I upgraded to the SDS, the timing and solidity of the sound improved dramatically. I then found that using a single belt directly from the motor to the table actually outperformed the three-pully design originally designed for the table, perhaps with some trade-offs, i.e. voices sound clearer and better-defined, but piano may have a little less air and realism.
Finally, the table sits behind the speakers, particularly the left speaker. Moving the speaker forward a few inches seemed to significantly clean up the sound, so vibrations from the back of the (B & W 803) speaker may be muddying the water. My other components are Spectral DMC-20 and DMA-180 and MIT/Spectral reference cables.
Like I said, I am glimpsing the potential of this setup, and the music is starting to clean up and jump off the record, but it's just not quite there. I feel like I'm missing something simple and would like advice before making a lot of changes. I think I've set the cartridge up properly with regard to alignment, azimuth, VTA and no anti-skate. I have not removed the damping trough yet, and that is the next thing I was thinking to try. I am planning to try to further isolate the table from the speakers - the cable lengths prevent me from totally moving the preamp and turntable. I was also considering using different belts or string/dental floss etc. Another possibility is investing in a single-motor flywheel, which also would not use the three pulleys included with the TNT turntable. But, I feel that there is something simple and straightforward with the front-end that I am missing. Any advice?