Mine is quite responsive. It uses cast cast scripts and only 1 or 2 views per dashboard. Nearly instantaneous when using the sticky navigation buttons.
I do find the dashboards lag a bit sometimes when called by my recast flow in Node Red but when I toggle the script again from my Moe’s smart knob stick to the back of every nest hub I have, it speeds up again. It is like the devices need a restart to clear the cache or something.