Record clamp/weight and turntable speed

@mijostyn  The “sound” of a turntable drive is BS, you hear the sound of cartridge/tonearm mainly. The rest is speculations. Speed must be stable, period.
Even very cheap direct drive can’t be affected by the weight of a record clamp.
Not every Direct Drive have a high torque and immediate start at constant speed. Not every DD have a high mass platter. My luxman pd-444 or Victor TT-101 are not high torque turntables.
Technics is a high torque turntable, even if you put 3kg on the platter the rotation will be stable with immediate start!
Belt drive can be affected by many factors and the speed is the main issue, read tons of comments on audiogon from BD turntable owners, those type of drive is notorius for not stable rotation. Most of BD turntables on the market is junk and people love it!

@mijostyn  I did indeed download the RPM app and discovered my main VPI HW-19 tt runs around 33.64, while my Craigslist marketplace let-the-kids-use-a-turntable TT runs around 33.17.

Without a dedicated clocking device, do all tt's vary in their speeds like this?
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Heavy clamps increase the wear on the bearing.
There is no reason for them to be heavy if they have correct mechanical design.  Screwing onto a threaded centre pin is a much better approach than using mass to hold the record down.

@simao   It's really quite difficult to get a TT to run at 33.333333 rpm.
And a cogging computer controlled direct drive is not the way to do it.

@chakster     3kg???   Many TTs have platters weighing 25kg, some much more.
Over-engineered glitzy TTs with extra bling are one of my pet hates.

Simao, there are many things that can push the speed a little one way or the other such as temperature and AC line drift. Very few turntables are right on unless you can adjust the speed. Some modern turntables actually have a computer monitoring the speed and making the adjustments for you in unnoticeable increments.
@chakster , you are right. It is the tonearm and cartridge that produce the sound and DD turntables make them sound lousy which I can easily demonstrate to you in person. The last thing you want in close proximity to a cartridge is a pulsating magnetic device. Not to mention that I know of no DD turntable that is adequately isolated making matters even worse. But everyone knows by now how the two of us feel and neither is going to change the others mind without a demonstration that can not be performed. So it is a moot point.
Clearthinker Theoretically I agree. The more weight you place on a bearing, the shorter will be it's life span. (except for magnetic and air bearings). Threaded reflex clamps are the way to go for sure unless you have vacuum. However the bearings of most good turntables are very over-engineered and unless subjected to trauma you could measure their lifespan in centuries. My Sota Sapphire was as quiet when I sold it as the day I bought it 40 years previously. That is listening to the sub chassis with a stethoscope. I also agree on your bling thing. Turntables are meant to be heard, not looked at. They only need to be tidy and well built/finished, just one of the reasons I like Sota's and Dohmann's. Tricking one out to make it look like Star Wars is a waste of money, money that could be better spent elsewhere. 

Mijo, I am getting a little excited about the idea of a "pulsating" anything, anywhere in my vicinity, given the dearth of human to human contact that characterizes my day to day existence during the pandemic.  Anyway, I have to disagree with my DD co-conspirator, Chakster, on at least one issue.  I do think that each type of drive system has its own sonic signature.  Guess which drive system I prefer.  I also think you ought to see someone about your fear of pulsating magnetic fields.  You are surrounded by magnetic fields, unless you live in a cave.  But seriously folks, I bought an EMI meter just to satisfy my curiosity about EMI in the vicinity of the cartridge that might be generated by the motor of a DD turntable.  Detected nothing at the platter surface.  This was with a Technics SP10 Mk3 which sports the largest iron-core motor of any vintage DD and probably at least as large as that of any modern DD.  I also checked my Kenwood L07D, which uses a coreless motor.  Nada.  Of course this observation is subject to the sensitivity of my meter. The fact that you personally may fear the negative effect of a DD motor on cartridge performance is not per se proof that there is any appreciable effect in reality.  The engineers that designed DD turntables in the first place were not unaware of the potential problem and were aware of how to use shielding and motor orientation in order to eliminate the problem. They did a good job.  Now, can there be a cheap, poorly designed DD turntable that adds its own noise to the audio signal?  Maybe.  Can there also be a cheap poorly designed BD turntable that is wildly inaccurate speed-wise?  Absolutely yes.