What about these newer "MDF" tables? Rega p2?

In a TT, the main bearing and drive system is the key issue, not the suspension. I have a high end TT that has no suspension at all. A suspension is simply a type of vibration isolation.

I think that the MDF construction of many newer entry level TTs is a cost cutting measure.

Older Rega Planar 2 TTs came with glass platters, but not with the RB300 arm. They came with RB200, or RB250 arms. The RB250 is a better one than the RB200. The Rega Planar 3 came with the RB300 arm.

Suspensions vs non-suspensions is a thing that audiophiles have argued about for years. Both types have their good points and bad points. I would say that it is a personal choice. Generally, lower cost suspension TTs are less prone to vibration, but are more complex in construction, and may require adjustments. Non suspension TTs may have more vibration issues, but are less complex, and need no adjustments of that type.

I generally believe that in a cost-oriented TT, the less parts the better, because every part costs money. If they have to make alot of parts and complicate the assembly labor process, the TT will either cost more, or they will have to cut cost in the important areas of bearing, motor, and platter, and possibly tonearm. That is, if they are going to keep the same entry level price point. You can see that many makers are going to MDF already, to cut costs. If they had to include more parts and labor costs for a suspension, then the price would surely rise, or the quality of the important parts would surely fall. No free ride.

I tried some experiments with plinths some time ago, and mdf is good stuff. just because it is cheap to obtain and machines like a dream can be misleading, when one thinks about the requirements of a tt.
I liked it better than plain acrylic, much better than plain steel, in fact, I would say that you would pretty much have to use a constrained layer construction of the RIGHT materiels to do better than mdf. (this is plinths and armboards). The only drawback to mdf is that it sensitive to wheather and temperature, and not really durable unless it is properly coated. But than again, acrylic is also sensitive to temperature changes.
I hope this puts things in a perspective for you.

An older Planar 3 with the unloved RB200 arm is a good deal on the used market. But one cheap, pull the arm off, and install the Origin Live modified rb250. Good table/arm combo. There is one on ebay right now with a buy it now for 300 and opening bid is 200.