Well, the hardening, just as with Tor Browser, does break some sites. It comes preinstalled with NoScript and uBlock Origin, the former of which you will either have to learn how to use or disable, depending on your wants for privacy. While it doesn’t include some of the anti-features of base Firefox, it is still based on Firefox so it will have similar performance for similar tasks.

Personally, I use Mullvad for most of my browsing, and Firefox for a few specific things (like staying logged into site long-term and such).

It’s available as a flatpak via Flathub for an easy installation, otherwise you can check https://mullvad.net/en/browser/linux for distro-specific installation instructions.

I use Mullvad Browser. It’s maintained in coordination with the Tor Project, and is essentially the Tor Browser with Tor itself stripped out. Same browser fingerprinting protections, however, among other things.

This was already posted here, and the original post has a paywall bypass link