A little history....
I had done a test comparing the FCS Fusion box to the Probox, Both embedded directly in 1.35# EPS a few years ago. The FCS box failed that test. The Probox passed it. I've been using all Probox since that test.
So this week, I decided to see if I could bring the FCS II box up to Probox durability levels by adding a Corecell cassette, then embedding in the EPS. The Probox would remain embedded directly in EPS, no help from any Corecell cassette. Watch the video to see what happens.
I can now offer FCS II finboxes to customers, if they insist. I still prefer Probox. It's a cleaner installation for me, plus the bonus of some fin adjustability makes it a winner. Those slight fin adjustments make a huge difference in a boards performance.. There is a 5oz weigh advantage going to the FCS II installation.