I for one really like what the VPI clamp & ring do for my turntable. (in fact I built my turntable around it)
The ring & clamp increase the record to platter contact, flatten warps, provide more stable speed, and most importantly - all of these things together make the stylus track the groove correctly.
When the original was cut on the lathe, it was at a steady speed, on a level surface without undulations (warps) of any kind.
You can look at a turntable with the VPI ring and clamp on it playing a good pressing and you will usually see zero movement..(this to me is the single most desirable thing that a turntable can do - it means it is tracking like it was cut.)
The combination of the VPI ring and clamp brings the sound to life on my rig. (much better than without it)
Your mileage may vary..
Enjoy the music.
Joe