Definately new, they are made to better standards and are much thicker, also guaranteed not to crack for 12 months by Greg.
But not every ramp is available new so sometimes you have to settle for NOS
+1. Added greg's ramps to FH and they are a different creature quality wise is every way. Also got some new AFM ones (haven't fitted them yet, gotta get off my a$$ one of these days and do it) but you can see the difference at a glance. NOS is great for non-reproed ones, but I would go repro in an instant if there's a choice.