I know they were only carrying 35" size initially and the set I saw on a Discovery showed they did work a treat. My local tyre guy who sourced the set for the disco said the guy that was the distributor for them does not do them anymore and isnt sure who does them?? They worked out to be cheaper than Simex and as far as I could see had slightly bigger voids between centre blocks so would think they may work a little better.
http://www.silverstone.com.my/tyre_mt117Xtreme_spec.asp

cheers
Rex