I was viewing https://wiki.mozilla.org/Security/Sandbox https://wiki.mozilla.org/Security/Sandbox and it appears that Firefox on Linux now has some kind of sand

I was viewing https://wiki.mozilla.org/Security/Sandbox https://wiki.mozilla.org/Security/Sandbox and it appears that Firefox on Linux now has some kind of sandboxing. I presume it's not as good as Chrome but I'm sure it's raised the security level significantly. Realistically, how much danger am I in by using Firefox?