It was not intentional.@fsonicsmith I didn't get the impression is was. I just though I should point out the issue, since the 'table is quite different if you have a good arm on it.
As far as the mat goes, its pretty easy to demonstrate with nothing more than a few different mats and a turntable that you can hear differences. You don't need amps or speakers for that. What a weight or clamp brings to the 'table (if you see what I did there...) is helping to keep the LP in contact with the mat so it can more effectively control resonance in the LP. Vacuum works even better, but the vacuum system I had damaged a lot of records (ticks and pops due to dirt pressed into the grooves on the backside of the LP; this was over 20 years ago) so on that account I've stayed away from vacuum systems.
The problem as I see it is that many aftermarket platter pads are no better than the one that they replace. So you get variable results. But if you hear one that actually does what its supposed to (as I described earlier) then there is no going back.