I switched to Firefox Dev Edition last year and havnt gone back since. It really does have a noticeably smoother feel to it. I do miss certain Chrome dev tools such as Lighthouse, however its not a difficult transition at all.
You can always boot up Chrome for the few times a month you need lighthouse. Run the test, get the data, then quite chrome.
That's what I do. I use Firefox as my daily. But I still have chrome installed and boot it up probably once a month. So it's there, but I don't stay logged in, and I don't use it very often.
One issue with Dev Edition is that it shares the base code with Beta. With the new 4-weeks release cycle, most of QA testing now happens in Beta, meaning the chances of serious bugs in Beta and Dev Edition increased quite a lot.
Previously, most of the testing happened in Nightly, and only tested code was moved to Beta and Dev Edition.
I use Chrome to benchmark my local version of a website. The use case is very limited, because the results fluctuate a lot depending on the overall load on my machine (including the dev server), so I usually do three passes on the master branch of my project, get scores like 53, 56, 51, then switch to my development branch, three passes again, if I see e.g. 58, 56, 61 then it's fine, if the results are noticeably lower than master then time to investigate.
In any case we have a dedicated environment with lighthouse-ci and this is where the real pre-release benchmarks are executed.
I hope more people take the leap.