A 7' Directional is a fun cruise (I have two - they're soooo good in the right conditions), a modern TT is like being on trolley tracks but these 'Flatties' are a different animal.
I am clearly not good enough to ever fly one of these without straps. I spent half an afternoon falling on my face and not being able to deep-water start 'till I gave in to these neoprene crutches.
Here's two schools of skim. Mike Geldart, an eastcoast champion, shaped the carbon 'stealth' board on the right, and the other is from a young shaper with a different idea. They both work as skimmers, but the white board is perhaps a little more fragile in the shorebreak - but that's not our element.
I've had a couple of hours on the Geldart and can actually TT it. As you can imagine with the width - they're both an easy start. Mike's board has very sharp turndown rails and hooks up well. Unlike a kiteboard, the highly rounded outline has the board spinning in place. I put a small single fin on the rear to calm it down a tick. It's kinda interesting to rotate it and you can also jam-stall the board and then take off again.
As a kiteboard, it works quite well, but I suspect you will be hauled for a high speed downwind if you get caught in heavy air, as it would be much harder to hold an edge vs. the average TT.
The second board has channels which should help it track, but suprisingly it was harder to control. I used a new setup where I can glue the pads and straps rather then puncture the skin. I'll glass on a couple of fins to make a twin-zer out of it and maybe be able to test it in FL later this winter. (I'm out of the water - now that it's below 50f.)