I have seen 3/4" ply, 3/4" MDF and even 3/4" particle board with melamine on both sides. I know festool opted for the MDF, obviously not because it is lighter than 3/4" ply, but perhaps because it is less expensive too. The particle board with melamine gets a really, really slick top and would be excellent in glue up (clean ups) but seems it would have a tendency to chip out as well as the plywood. Thoughts or observations? Remember will be drilling plenty of 20 mm PARF holes and have a semblance to the Paulk support underneath it.