How important is low W & F performance anyway?

@phoenixengr 

"I purposely did not list any of that information to prevent undo controversy."

Isn't that what you've created already? From where I sit it compromises your credibility.  When you make these exclamations about a manufacturer's claims I'd rather deal in facts and not nonsense.

As I said, the choice is yours.  It hard to imagine how I could possibly care less either way.

@faustuss There is no question concerning Bill’s credibility.  It makes no difference whether you find his information useful or not.  It certainly comports well with my experience and with what I have been learning since acquiring AnalogMagic.  Take it for what it is worth.  

https://audiokarma.org/forums/threads/checking-speed-wow-and-flutter-on-a-turntable.1000956/

"At a playback radius of 100 mm (which is roundabout at the middle of the LP playback area), a barely visible eccentricity of just 0.2 mm (which also happens to be the tolerance of most records standards) would already cause a wow of +/- 0.2 % peak or respectively ca. +/- 0.14 % effective/RMS."

-wondering how such low W&F can be measured at all! 

@westcoastaudiophile  @phoenixengr 

At a playback radius of 100 mm (which is roundabout at the middle of the LP playback area), a barely visible eccentricity of just 0.2 mm (which also happens to be the tolerance of most records standards) would already cause a wow of +/- 0.2 % peak or respectively ca. +/- 0.14 % effective/RMS."

You bring up a very good point.

Discussions I’ve had with Bruce Thigpen ( Eminent technology, Mapleknoll etc ),

are that records are useless for measuring TT performance for the reasons quoted.

He uses a rotary function generator to measure the actual platter speed to measure  wow and flutter etc.

Bruce Thigpen on wow and flutter

Reviewers have incorrectly attributed wow and flutter to the turntable. Since the advent of the belt drive turntable, wow and flutter has been purely a function of tonearm geometry, the phono cartridge compliance with the elastomeric damping, and surface irregularities in the LP. In our own lab we have measured many high quality turntables using a rotary function generator directly connected to the platters of the turntables.

The measured results are usually an order of magnitude better than the results using a tonearm and test record (conventional wow and flutter method). Further proof exists if you take two tonearms, one straight line and one pivoted and mount them both on the same turntable. The straight line tonearm will give a wow and flutter reading with the same cartridge/test record of about 2/3 to 1⁄2that of the pivoted arm (.03% < .07% to .05%). This is because the straight line tonearm has a geometry advantage and lateral motion does not result in stylus longitudinal motion along the groove of the record.

Another proof is to take two different cartridges, one high compliance and one low compliance, and take measurements with both using the same turntable and tonearm. The reading of wow and flutter will be different. All wow and flutter readings are higher than the rotational consistency of the turntable.