Direct drive/rim drive/idler drive vs. belt drive?

The flaws in the way most vinyl was mastered will far out weight what 'perfection' that you chase in the TT design. Once you arrive at the 'perfection' design, it will be time to move on to a base that is no less than a $10K electron microscope table. Then on to other parts of the chain. Please, just enjoy the music.

We will always have different opinions about what platter drive is the "best" because we see here -again - different "schools".
I - again - just want to mention the fascinating idea first proposed by japanese audio engineers about using the string on heavy platter and working with a WANTED and precisely tuned "slip".
This works just great with a precise platter of considerable weight and inertia.
The string with minimal grip and minimal tension does indeed minimize any speed alternations, transmitted vibrations and just have to prevent the platter from loosing speed.
The (only...) trade-off is a long time till constant speed is obtained (1-2 minutes).
On the other hand we have the minimal possible influence from transmission, motor etc towards the platter.
Its the basic principle behind the big Micro Seiki, Melco and Epic turntables.
Add to this the concept of putting the bearing free from horizontal force (counter-bearing) and you have a smooth TT principle which just needs a considerable amount of space, weight, precision tooling (these 3 = money....) and care.
But - as in most other audio "fields" - different "schools" will favor different concepts and "models".

In my opinion theory doesn’t really matter because we can debate it forever and never come up with a consensus. All that really matters is what sounds best to the listener.

The "whatever sounds good" opinion is a consumer attitude and there's nothing wrong with that but can never work as and apply to science nor truth seeking. I certainly hope people who do manufacturing has done more research than just "whatever sounds good" and came up with more educated decisions. Therefore I completely support the kind of work Mr. Mark Kelly has done and appreciate the time he spent in experimenting and, even more importantly, sharing his findings in print with us. Thank you Mr. Kelly.

I have experience with all three drive systems and they all can sound good but, right now, I completely reject using a soft rubber belt. If a turntable has to use something that soft to filter vibration and masking speed irregularities then it needs a better motor, period. In the last decade in belt-drive manufacturing, much has been belabored on fancy platter, thick and shiny, and bearing, thick and shiny, but little has been focused on the actual motor. Enough with wimpy toy motors already!

Hiho :-)
y.s.: >> Enough with wimpy toy motors already! <<

I guess you are fully aware that this type of wimpy motor is supposed to do the same thing as a soft (and long?) belt already. 'Mellow out' any kind of speed variation that's occurring. It screws the dynamics but it sure will be 'smooth'.
Greetings,