Coming from a District v2i to the 20" Threshold it seemed like there was less footroom at first. I think there's something like a centimeter difference. But then I got used to it and realized that it's wider and better.
The concave is actually noticeable and is great feeling as well.
The bottom is literally the perfect bottom for a scooter, it's super wide front to back and it's super thick too. The dropouts could be wider, but at the expense of easy back wheel installation. The front end geometry is very nice as well. As someone who does a lot of 5050 grinds, they became noticeably easier with the wider bottom. Wider than a District.
Headset installation with the integrated headset cups is a breeze and the deck is just really really solid overall.
10/10