Thoughts on the various platter materials used in Pro-Ject's midrange turntables?

I've been looking at Pro-Ject's mid-priced turntables and it has got me thinking: which ones have better platters for sonic performance?  Specifically, the models, all which have different platter materials are:

X2 - Acrylic ($1,699);

The Classic Evo - Aluminum (Precision balanced TPE-damped) ($1,999);

6 PerspeX SB - Vinyl/MDF sandwiched platter ($2,799).

Doing some general searches online, there seems to be high praise for acrylic.  A lot of bashing of aluminum and not great comments regarding MDF.  Is it possible that the cheapest turntable (X2) has the best platter?  Obviously, this discussion does not take into consideration the other differences with the turntables, including cartridge differences.  But just thought I'd get some insight specifically on the platter issue.