Record Mats In Combination With Weights

The purpose of a mat and weight/clamp are to dampen the record so that it does not resonate under the stylus.

It is a lot more complex than that.
If you have a reflex clamp or heavy weight with washer under the label, then you are coupling the record to the platter or platter mat.
A concave platter/mat with centre weight/clamp  achieves the same.

Many aftermarket weights with a flat surface/no washer are doing nothing .

Excess weight will wear out a bearing prematurely except for those that use a magnetic thrust bearing. 

Unless you have a high mass platter bearing specifically designed for the additional weight.

Before setting up the Soverign I used the Gravity One on my old table. It was no contest. MUCH better truth of timbre, greater dynamics, impressive detail, extension, just more of everything you want and none of what you don't.

Hyperbole to the extreme.
The Gravity is just a lightweight tuning device that sits on the record.
It does nothing to flatten records, or couple them to the platter surface.
They would have you believe that if you put a piece of flooby on the record label it will improve the stylus performance  2 inches away on the first track. A 1/2 cup coffee or a lump of your childs playdough sitting on the label could be just as effective.

I have heard the Gravity on a variety of turntables - it is garbage, a con.
For comparison i have in house weights/refelx clamps from Final audio, Micro Seiki, Sota, Goldmund, Audiocraft and many others. I laso have a variety of mats in the house from Final audio, Micro Seiki, SAEC, Godlmnd, Sota, Seisin, Sumiko and many others.

When I heard the Gravity we tried it on a variety of mats and turntables.
Yes it slightly altered the sound, improvement - no,.

The worst record weight I have ever heard was the much vaunted "Stillpoints" - again tried on a variety of turntables and mats - worse than useless, although it added a little sharpness it muddied up the upper midrange lower treble by some degree compared to other designs.

There is no "best" weight or platter mat becuase the outcome of any of these aftermarket products is going to depend on the platter construction of each particular turntable and the tracking ability and sound quality of your particular arm/cartridge/phono combination.
This is why I keep  library of platter mats and weights/clamps on hand. It can be illuminating to revisit them from time to time when I am setting up turntables.
To believe that a specific weight/clamp solution will be effective on every turntable no matter what the construction is illogical and foolish.

I have heard the Gravity on a variety of turntables - it is garbage, a con.

Hyperbole to the extreme.

For comparison i have in house weights/refelx clamps from Final audio, Micro Seiki, Sota, Goldmund, Audiocraft and many others. I laso have a variety of mats in the house from Final audio, Micro Seiki, SAEC, Godlmnd, Sota, Seisin, Sumiko and many others.

A 1/2 cup coffee or a lump of your childs playdough sitting on the label could be just as effective.

See what I did there? Used all your own words to demonstrate just how easy it is to throw insults that all boil down to "no you’re not I am neener neener" which frankly is a more respectable reply than you deserve.

@dover

Well, foolish or not, the sound quality from my setup suffers on everything I play without those options.  Maybe I have been just lucky?

I have the Denon DP450 with the Ortofon 2M Red. I am now using the Archomat rather than the rubber mat that came with the turntable. I use the  Fluance Hifi  weight and haven't determined any issues with turntable function.  I have tested albums with the Fluance Hifi weight, both on and off. With it on, before I got the new mat and the sound quality was more structured and it solved some hissing noises and hollow sound effects. The Archomat adds a new layer of structure and clarity.  Based on the positive attributes that have been revealed, I take the position that these items are a positive influence on the system I am using.

Right. Because you are listening. But not lucky. That's just the way it is. Far as I can tell anyway. Every single thing I ever tried was better than nothing, than just a record on the platter. When I first brought this up to DJ Casser in the early 90's he made me a carbon fiber disk with a hole in the middle, crudest thing he ever made I bet. But that's the way it is when you test, doesn't have to be pretty. It worked, and that was enough.

Since then I tried lots of things. Playing a record generates a tremendous amount of vibration. Never seen any measurements but I bet the stylus in the groove generates far more vibration than the bearing, motor, everything else all put together. This should by the way be obvious and uncontroversial. Play any record, you can hear the music clearly just from the cartridge body vibrating. Can't hear the motor, platter, bearing, plinth, anything else. Just the cartridge. Main source of vibration.

Mats, clamps and weights all help to control this vibration at least in the vinyl. Things like OL Cartridge Enabler or fO.q tape can help with the cartridge. All these things help. The challenge is these vibrations run across the whole audio spectrum and dynamic range. It is super easy to dampen some enough to hear improvement. That is basically what all the different things do. What is super challenging is to control equally well across the whole spectrum. This is harder to do and also a little harder to hear. When one or a few things are made better this stands out. When everything is improved equally well the full nature of the improvement can actually be a little less obvious and harder to hear. Or another way of saying it can take a while to appreciate. But these are worth the effort because they are exactly the sorts of things we appreciate more and more as time goes by.