I beg to disagree. The figures give an indication of wow and flutter, which is useful.
Since, however, you think them invalid, perhaps you would like to share with us what would be more appropriate to measure, and how? Never forget that W&F at a certain level is audible and can affect your enjoyment of records.
Perhaps you are missing my point. But i can explain further.
Let's suppose you have a Garrard 301 with an idler wheel that is slightly twisted. It would probably measure about 0.2% on combined wow&flutter. But most of that amplitude (0.2%) is simply very low frequency wow, while the rest of the flutter components will be (and i can bet my life on this) less than 0.05%. After all, this is a tt with a heavy platter coupled with a motor of great inertia.
This 0.2% wow probably won't bother you unless you hear a sustained piano note that lasts for a full turn of the record. Because the flutter -that is, the speed variation on higher frequencies- is still very low.
Now, returning to the "weighing" thing... A belt-drive Technics SL-BD30, with its light platter and coggy, small DC motor, has 0.05% weighted W&F. A belt-drive turntable with a smooth and heavier AC motor and a circa 2.5-4Kg platter would probably measure 0.03%-0.05% under the same weighting, but you can bet there is an audible difference in speed 'smoothness' or 'timebase stability' or lack of 'jitter' or whatever you want to call it.
So, all in all, i'm starting to think that instead of looking at the weighted W&F figures, we can simply take a look at the construction of the turntable and have a good clue on how smooth it will be. As mentioned before, the arm&cartridge interaction influences, particularly if the combination is overly sensitive to the warp frecuencies (and arm&cartridge combinations are VERY different in this respect, because of differences in mass, compliance, and cartridge damping factor). Then, having examined the arm&cartridge, i'd say the speed smoothness will mostly be a function of the platter weight, motor inertia, motor 'coginess', and belt compliance (what i call 'belt bounce'), firmness, and/or slip on belt drive systems.
Idler wheel systems being similar to analyze with a quick glance of the eye. For direct drive, it is another story...
Of course, what i'm proposed is a purely subjective 'guess' on how smooth will a turntable be. For measurements, simply put: The reviewer/technician should use several test tones, at different frequencies, and give a graph of *linear* flutter vs frequency (that is, a spectrum plot), and this for each test tone. And then, note which arm and cartridge was used.
It's frequent to read posts with comments such as "specs are meaningless", "your ears are better than measurements", "use your ears", etc. It's a partial truth and a partial lie. It depends on what is being measured, how it is being measured, and how the final result is presented.