Ok. Just tried it and I am suitably impressed. It's a good first iteration. The main menus feel responsive and fast. I think there's more UX to be done (eg. more shortcuts ie. Practice/Qual/Race labels should link to their setup screens).
I'm still disappointed by performance and responsiveness in-session, though. It feels like they didn't optimize that like they did the main menus.
It's clear it's the same html engine, not custom, native graphics, and I'm okay with that but it has the performance drawbacks evidently.
A great first iteration of refinements. Keep going.