A $300-$400 turntable tweak

I think it all depends on the table, platter composition and surface material, and the ability of the tonearm/transducer to accurately trace the LP. I have tried 6 or 8 center weights/clamps/doohickeys, as well as a perimeter ring and found that on each occasion they detracted from my musical enjoyment in precisely the way Halcro has described - lifeless, boring, flat, sterile, dead. Perhaps folks who prefer these devices are simultaneously taming platters and plinths that are improperly damped or have resonance issues to begin with. Maybe this iron-handedness simultaneously "helps" other issues further down the chain, such as distortion/overload in the phono stage (a phenomenon more common than I ever believed) – any system freed from having to reproduce distortions is, subjectively, better sounding, even if the proverbial baby has been thrown out with the bath water. You never realize the baby is gone, since you couldn’t hear it through all the muck in the first place. I’m not saying destructive over-damping occurs all the time with a clamp/ring, but going too far is a distinct possibility.
Then again, maybe those of us with high(er) mass tables are already sufficiently damping the things that need control, and to further damp the sound is a step too far. As a disclaimer, I've never personally tried a vacuum platter deck, but every time I've heard one, I've always felt that the sound was overly damped. YMMV and all that. Have a nice weekend.

Halcro is right with the outer ring. I was never mad for it after listening.
Vacuum is a bit different, different depending on the idea behind and some other solutions. Basis for example uses low sucking force and has an extremely clever made platter with an superior suspension. Here is definitely an improvement to hear, still full of live with all tonal details.

Henry - it must have been a difficult 3 weeks for you wondering where all the music went :(

I used a ring clamp for a while and while I didnt think it detracted I didnt find it an improvement either. I have since then used Sota vacuum tables. I will never go back. I think youll find most vacuum table owners feel the same way. Who knows why. Its also possible that some like a little ringing as it adds "liveliness" to the sound and can be mistaken for "air", this is sometimes true of micro phonic tubes which in some cases sound more open.

You're right Chris.
Three weeks of un-fulfillment without being able to pinpoint a reason is frustrating.
The strange phenomenon is that the 'sins of omission' are not instantly audible when one inserts the outer ring into the system?
The return of the air and 'magic' is instantly audible upon removal of the outer ring??!
Perhaps this is one of the reasons that blind testing is so difficult and unpredictable and, in my opinion, unreliable?