Does the Deepgroove subplatter work for a Rega P5?

I have been told at another forum that there are really no worthwhile upgrades to the P5 other than the TT-PSU.

However, I have a hard time understanding how the Deepgroove subplatter would not be worthwhile over the plastic crap that sits under the P5 platter...if, in fact, the Deepgroove can work on a P5.