There's fans of both machines, and I reckon the bottom line will be, what machine you feel will do the best job for "you".
Best to research both, what they do-don't do. One consideration, is the unexpected possibility of failure down the road. Can the machines be repaired? By the end user, or?
I'm not completely sure of this, (so any of you Nitty Gritty gurus, please feel free to chime in), but I understand that many, if not all of the NG machines have permanently sealed cases, meaning to get inside, one resorts to a Dremel Tool, and Plastic Glue for re-assembly. Once inside, can the the needed repair parts-components be gotten from NG?
There is not a problem getting any of the needed repair parts from VPI, or a VPI Dealer, for any of thier machines. And some of the main components (Platter Motor-Vacuum Motor) can be gotten from places like WW Grainger for a lesser cost.
Many of the most expensive RCMs on the market (Clearaudio, Hannl, Loricraft, K Monks) use a somewhat similar method to VPI in one respect, being that the LP is supported on a Platter. But I believe some of these use a different material, rather than Cork as a Platter Mat. I feel other materials could be used to better this IMO shortcoming, such as neoprene, or perhaps as some others have done, the addition of another, seperate Mat to lessen any chance of cross-contamination.
As I said, research the features, and then one can hopefully make the best choice for his/her needs. Mark