We've used both, and they have advatages and dis-advantages.... On a recent hunt where the weather turned to freezing-rain. The Wisker biscuit was completely useless once it "froze up", as was a RipCord. The Octane was the only rest that remained "shootable" in freezing rain. Those data points should be kept in mind if you plan on hunting in foul weather.
All thngs considered I have replaced all of our Wisker Bicuits and Hostage Pro's with RipCords, and all my shooters love them, and say they would never go back.
Gone camping in the mountains of Afghanistan.
Will return sometime in early/mid 2012.