Cork is almost the perfect handle material. It does however absorb oils from your hand over time and can be almost as slick as teflon when it gets wet. The texture of the Redington handle looks like it would prevent that but so would washing your cork handle with warm soapy water occasionally. My concern about the composite handle would be that a certain percentage of people that use it will have reactions to the chemicals resulting in red and swollen hands. Not fun if you are one of those people but cork will prevent that.
It isn't really that new. Last fall, Jim Riggins and I tested two spey rods built by Gary Loomis. They had all composite grips, fore and butt. They were comfortable and didn't slip when they got wet. The rods were okay but I didn't have the right line. I'm not sure whether he (Gary Loomis) plans on building them for production or not.
You win the prize! Redington has worked with Winn Grips -- a golf club grip design company -- to develop the new rod grip. Specifically, they say: "PowerGrip amplifies casting power. The advanced polymer won’t slip when wet, feels soft in the hand and reduces fatigue. It also cleans easily, and doesn’t chip."
I expect to have the new Redington Vapen rod with the PowerGrip for advanced testing later this week. Sounds like I'll receive a 5-wt -- so I'll most likely be out on the Yakima next weekend with it. Let me know if anyone in the area would like to give it a try.