It has included some privacy measures to resist fingerprinting like letterboxing and has more privacy focused search engines as default like searx. Also it takes out some firefox utilities like pocket which I don't really use

As for Mullwav browser I'm not really sure, it seems to be another reinforced firefox like librewolf

Btw, here is a detailed, technical review. It is in German, but with transtae and all the code, it should be understandable.

TLDR: It's good.

i prefer to use librewolf as my everyday browser, while using mullvad as my browser for other things that dont require tor i like to keep things separated, personally

I'm not really sure, I haven't used it. In fairness, I only use librewolf for incognito searches, not as a daily driver

Just to be clear, are you saying Firefox with fingerprinting resistance used in conjunction with Arkenfox user.js provides fingerprint unification, similar to what Tor browser does? I'll have to check that out.

I think both approaches are valid tbh. Having a unique fingerprint obviously uniquely identified you, but if it's randomised then your browsing sessions can't (in theory) be linked.

Firefox has a weaker sandbox than chromium and less mature site isolation and therefore has lower security. privacy is a different story, but remember you're only as private as you are secure so Firefox is inherently not that private assuming a malicious site escapes the sandbox.

I'm fully against chrome's growing monopoly as well as Google surveillance capitalism but let's not be so dramatic with the "google mother ship" nonsense.

using chromium as a base does not equal data being sent back to Google, just like using Android as a base doesn't inherently send data back to Google.