This is pretty much a dead string, but I though I would throw in my 2 cents. Yesterday I got a bug and modified my RP6. I have always had the table on a 3/4" piece of quality birch plywood. The plywood is sitting on pink bubble pack. That was a huge upgrade in itself. Once every 4 or 5 months I replace the bubble pack as it shrinks. These are the small bubbles, not the large ones.
Wow. $11 invested and the noise floor dropped like no other mod I have done in the past. I have a few friend with systems in the 100K to 200K price range. Yesterday was the first time I have been able to turn up my vinyl setup and get that hyper analytical resolution and volume, without there appearing to be all sorts of grunge in the way. I don't know why I did not do this a long time ago.
FYI, I also found a couple pieces of 2" thick acrylic that I stuck under my monoblocks as platforms. That also lowered the noise floor and increased resolution. Not near as much as isolating the TT motor from the plinth, but it was noticeable. I got the Acrylic for $40. That was a steal. A sheet was $1,800.