They both are intermediate snowboarders who have never skied. One of them is switching because he's a big lollerblader and wants to do rails. One of them doesn't do much park other than the occasional box or small jump, and he mostly just kind of rides groomers. But he wants twins.
I notice the recoil has rocker. Now, if it was me, I would want rocker because holy shit it's fun. So I'm leaning towards the Recoils. But the 6th sense is a traditional cambered park ski which i think most of us had for our first twins so I'm not sure if you can really decide for a beginner that they want rocker.