Some thoughts after using preview for a bit:
- The UI/UX feels snappier and more responsive. This is particularly noticeable when inputting things in the address bar.
- I am not seeing much difference in rendering speed relative to regular FF (both are good on my SD625 device).
- Native dark mode is definitely an improvement over my 3rd party dark mode theme for mobile (yes, you can actually theme Firefox for Android). I wish FF would switch based on local sunset/sunrise (ala Nova Launcher), but it’s not that big of deal (they do support alignment with system theme on Pie).
- I found the bottom placement of the address bar awkward at first, but it seems to be an improvement once you get used to it.
- Default tracker blocking is no replacement for UBO. Lack of addons is a big drawback for Firefox Preview.
I will most probably switch once Firefox preview starts supporting UBO.
EDIT: Some screenshots: