The one with the suede knee pads is the latest model :) The knee pads were brought out because people were complaining it was slippery and hard to keep position in.
To get one without the suede, you need to buy second hand.
I have a 500CC without suede on the knees and I LOVE it, no issues with slipping at all - but I jump in full seat jods so that helps. My dressage saddle is full suede and I HATE IT. It's great for when the horses are being stupid, but I really struggle to keep a good position in it and I cannot sit the trot to save my life :/