I have used 2" solid maple and am now using 1" slate. I prefer the slate because of better dynamics and pace. By comparison the maple shelf sounded slightly muddy and was subjectively slower.
The slate sits on top of a Mapleshade Sampson rack with Mapleshade Isoblocks (cut in 1/2 thickness) between the rack and the slate. The rack sits on carpet over concrete in my basement listening room.
Jeff C. passed on a tweak to slightly unscrew the Stillpoints feet from the bottom of the table. Try this once you get your table and see if you like it.