I'd like to throw my 2 cents into this conversation. I own the Raven one that I have tweaked out quite a bit. And based on what it sounded like from when i first got it (which was very good) to where it is now is a rather large improvement.
I think the idea of abandoning this table at this point is a bit premature.
First I would try the above suggestions regarding replacing the rubber belt as an experiment, since it is almost free. The mylar Doug Deacon discovered and posted about is a great place to start, and I posted some info in that thread about an easier to use etching creme to remove the silver.
I replaced my standard feet (obviously you have stillpoints) with a Sistrum Sp-1 brass stand. You'd have to get a larger one for the the AC-, and possibly raise the motors up on something. This was a large improvement in speed and definition, and 1 point I added even drains vibration from the underside of the metal bearing.
Then I added a Halcyonics platform underneath the SP-1, which clarified so much of the spectrum I didn't realize was being colored by vibration. The Sp-1 acts a vibration synch into the Halcyonics, which Isolates it from the outside world. Once you hear active vibration cancellation, (at least in my building/setup, it's hard to go back.
I have since added a copper plater top (which the AC already has) and a TTweights peripheral ring and weight.
And the last thing I would suggest is trying the fantastic Strain Gauge cartridge system (which I sell- disclaimer). It gives so much resolution, and seems to provide great synergy with the TW sound. There is so much detail and information being thrown at you, sometimes I have to swap out to a less extreme stylus contour, to purposely gloss over some of the details in poor (or worn) pressings or recordings.
I also think it's interesting that Mordante has heard all of the TW tables, and feels they are close in performance. Sometimes I wish I had gone for the Raven AC, but after reading this comment, I feel my choice of going with the Raven One and using the savings to add the very best peripherals I could was a wise choice, and makes me feel confident that my analog setup doesn't need to change (meaning I can focus on other areas of the system). Best of luck.