I have tried several different platters on my TNT. I have found that with my TNT, the original delrin/lead platter sounds much better to me than either the thick all acrylic or acrylic/stainless steel platters. Although the steel platters weigh more and may theoretically have added speed stability, I have found the lead platters have much better resonance control and liveliness. I found the acrylic steel platters have a ring to them I didn't like. The all acrylic platter just sounds dead to me. I didn't find any noticeable difference with the inverted vs. non-inverted bearing, as long as the older bearing is in good condition. I think most people hear an upgrade when replacing their old bearing with a new inverted one, just because its new. I agree that the ring clamp will help a great deal if you have many records with a lip warp. Personally, I just find it easier to get another copy of the record without the lip warp. I have not use the ring clamp myself, so I cannot say if there is any sonic difference. Some people find its use difficult. Regular dish warps are flattened by using the spindle clamp. Hope this is helpful to you.
Rick
Rick