I just upgraded my TNT to the classic platter over the acrylic and really like the sound personally. I'm going to listen for a bit then switch back, but what I've found so far is a slightly livelier sound as opposed to the acrylics somewhat "thicker" and "darker" sound. I guess it's a matter of taste. Keep in mind though that the acrylic I'm referring to is the clear or "whiteish" colored not the superplatter.
I believe VPI is happy with the machining properties of aluminium but thats kind of a given really. If you've worked with lathes for as long as they have they'd should have know this a long time ago. I think the quality of acrylic has probably gone down while the price gone up therefore not as reasonable to make TT's out of. This will affect a manuf. point of view as well.
As a last note the super platter looks better and the aluminium leave fingerprints in the worst way IMO
I believe VPI is happy with the machining properties of aluminium but thats kind of a given really. If you've worked with lathes for as long as they have they'd should have know this a long time ago. I think the quality of acrylic has probably gone down while the price gone up therefore not as reasonable to make TT's out of. This will affect a manuf. point of view as well.
As a last note the super platter looks better and the aluminium leave fingerprints in the worst way IMO