I thought the Physix was a bit underwhelming as a board, especially given the price. I had a lot of the same complaints as JYMV, especially with the cheap design of the internal weight. I ended up just keeping the plastic wrap on it, but that felt like such a compromise for a board that I paid nearly $700 shipped.
I also didn't find the mounting system particularly good or bad. Someone could have told me it was top mounted and I would have believed them.
Basically, the board is "fine", but for $700, I expected more than "fine".