Nice. I hadn't seen one of those. It looks like it cuts grooves that are ready for glue up. With a good fit, assembly is much easier, and you are likely to get stronger joints that may actually be airtight.
I don't have a table saw, so I cut dados with a router and a straight fence. I usually use a ½" straight bit and make two passes if I need a wider groove. In the real world, ¾" MDF or plywood isn't actually 0.75" thick, so I use the actual thickness of the wood I have to determine the width of the dado groove.