I tried it too just the other day. I did not notice any speed differences and navigating with bookmarks was clunky.

The Firefox web site says it will "eventually" be able to sync bookmarks, etc. with the desktop version, and it will require creating a Firefox/Mozilla account.

On a Mac since 1984.
Currently: 24" M1 iMac, M2 Pro Mac mini with 27" BenQ monitor, M2 Macbook Air, MacOS 14.x; iPhones, iPods (yes, still) and iPads.