G'day Mark G. What part of the world are you from?
I've had alot of dealings with Rayco for my Arborist gear and get to see and talk about their machines alot with Rayco staff. They look very impressive!
http://www.newagearbor.com.au/rayco_rc12.html is the Australian link to the stats and specs for the Rayco 12 inch. When I do get my new chipper, I hope to purchase their 20inch.