So, I have been out in various conditions now, from washing machine 1's and 2's to gentle rolling 6"s.
Observations so far:
The girlfriend enjoyed it in predictable 1's at a pace just fast enough to get the floor out of the water which kept her dry, with my back up against the transom I was very wet.
Her son (20 years old), who has been around boats his whole life (including small ribs) really enjoyed it, especially when I told him to come to my side and I slowed a little, turned on a dime with a nickel change.
It needs a different prop for flat water to go as fast as possible.
Definitely need to make a decent steering dampener in the rough stuff, very twitchy with minimal input, to the point of being a bit scary.
But the fun factor is through the roof!

So I had a ton of fun in the Thundercat last summer. I broke the floor in multiple spots at the end of the season, so I knew I had some repair work to do. When I pulled the floor panels out I was surprised at how much damage they had taken. Not really repairable, so I made a new floor section. The original floor was 1/2" foam with two layers of carbon on each side. With the amount of failure it sustained I figured I better make the new one much stronger. The new one is 1/2" foam core with three layers plus a Kevlar layer on each side plus three layers at the transom. I made it yesterday, just need to clean up the edges today, let it cure a bit, then see how strong it is!
I also found an old Evinrude basket case SST60. Waiting on parts to build the Nitro lower. Should have it mounted by Aug.

Looks like LOTS of fun

Nice! That thing must be a hoot!

I am looking for a little island hopper like that (with a bimini option).

Agreed, Looks like a lot of fun!!!