Platter upgrade for VPI MkIV?

Keep what you have. The difference is mostly the platter itself, not wether the bearing is inverted or not. I have the same platter that you have on a TNT6 plinth. It was an improvement over the thick, black, acrylic/lead platter. BTW, I believe that what you have is a MK5 platter. Acrylic/steel sandwich.

According to Mike at VPI in one of our conversations: "It is as good as any platter we make/made, including the Super Platter"

Mark, my platter was called TNT 2 when I bought it, it has no lead (that I know of) but does have a cork ring, and the 3 small micro-point adjustment screws. I think I've got the isolation and suspension worked out pretty well and I do have a SAMA and a SDS.
Frogman, I just received an email from Mike at VPI and he says as far as he's concerned, he wouldn't listen to anything but the Classic platter. Go figure. He did say that it is larger in diameter so I don't think it will work with my super thick armboard and ET arm.

The Super Platter and Classic platter indeed will not work with the ET-2 arm, as the platters are too wide. I had to ditch the ET on my TNT when I got the Super Platter.

Well... years later and much more experience later...

( I can't count on my many fingers, how many times I've read the phrase, "((someone)) at VPI said", ("You have one of the best platters we've ever made.) So, this phrase has little meaning anymore. In fact, it has no meaning because Harry has made SO many changes in such a small time frame,... how in the hell is an end-user suppose to know what they have.. or at the very least, how, what they have sound like, by comparson to what the hell ever that VPI decides to make public???

Since this thread arose, it turns out that upon my experience, Frogman was wrong! He stated the difference between a non-inverted bearing and an inverted bearing will not be the main difference. Wrong, wrong wrong!!!

I had a super platter on my VPI Superscoutmaster.....the changing to the Classic platter was a significant step upward...you didn't need super-hearing to hear the difference.  The soundstage opened up,  looking back,  highs sounded like they were non-existant with the Superplatter in comparison, the Superplatter was turgid, thick, and dead. The Classic platter's highs are not at all bright, just silky smoothe and fast. Get the Classic platter...I haven't heard the mag-lev platter, but I strongly suspect the difference between that and the Classic is not nearly as great as between the Super platter and Classic.