Sota Sapphire with or without vacuum?

I agree with above, Ive owned the whole line and currently have a cosmos IV. Ive also owned tables with periphery rings. I prefer the vacuum to any other system. I have never noticed any "dullness" but I have noticed the highs are rich and clean in comparison to other tables.

By "dullness" I meant that the reduction in higher frequency resonances seems to make the highs less prominent when using the vacuum. A quick A/B would indicate that without vacuum you get more "highs" but that really isn't the case.
The vacuum is better.

I'm running a Star Sapphire w/ vacuum - I've never tried it without the vacuum, but in general it has very deep bass, lots of clarity and a very smooth top. It sounds great!

I had a Sapphire w/o vacuum years ago circa 1989, one of the first. It was an extrordinary TT.

In the mid-90's I heard a Vacuum model, and I couldn't believe my ears. It cost so much more and was NOT even close. I think it lost its resolution and detail, and sounded dull, not warm, but dull. I would stick with non-vacuum.

The sound is sweeter with the vacuum
Once you go vac, you'll never go back. :-)