The vacuum on the Sota is only heard for about 3 seconds on startup, to seal the record, then reduces to maintain the vacuum. After it reduces, I simply cannot hear it without putting my ear up to the remote vacuum box. Plus, I dont understand the idea that a vacuum would drive dirt into the grooves. It would be the exact opposite, pulling the dirt out. And as to the pressure of the vacuum causing the record to grind down on dirt on the platter, the pressure is so much less than a clamp, and is spread evenly across the surface, not loaded at various points across the record like a clamp.
If maintaining contract between the platter and the record is a good thing, then nothing else works as well as a vacuum platter, and no vacuum platter works as well as the Sota, at least in my experience. It really is automatic and adds no compexity to the record playing experience.
Now, some may not feel that contact between the record and platter is a good thing. In that case, a vacuum would be the wrong way to go. Except it really does take out most mild warps much better than a clamp, and even larger warps if you run your fingernail along the edge of the record at startup. Once it gets that initial seal, it holds it throughout the side.
I do agree with you in theory that a small constant drag is probably better for maintaining a constant speed so long as the motor has enough torque to overcome that drag at all times. That would be better than a platter that fluctuates between being pulled and coasting. Sort of like trying to pedal circles on a road bicycle. Almost impossible to do, but is the holy grail of any professional bicycle racer for fluid movement.
Any thoughts on the difference between a Metacryl platter and a Delrin platter? it seems that Delrin is used in many areas to reduce resonance, and assuming no resonance is a good thing, Delrin might be a better material for platte construction.
I guess some of the earlier ugliness got removed by the moderator.