But probably time to take another peek.
At least Google does not also push you to create a Pocket account... ;^)
https://mozilla-services.readthedocs.io/en/latest/howtos/run...
(I still like having the option to run my own sync server though.)
With Firefox account, Mozilla is not selling any of your data data, a Google account not only is a goldmine of data to sell, but you're signing for a lot more services than just Sync itself.
If you honestly believe that Google is less or equal in terms of user data privacy as Mozilla, then I'm not sure I can convince you otherwise, but despite all the recent blunders, I still trust Mozilla more in this regard, be it with a watchful eye.
about:addons uses Google Analytics, and yes, I know Google promised Mozilla not to look at that data.
But either I have to trust Google that they don't use the data from Chrome's Enterprise and Chromium builds. Or I have to trust Google that they don't use the data from Firefox' about:addons and Firefox Focus, and that CliqZ doesn't use the data from Firefox.
If I have to trust Google anyway, I can just use Chrome.
and with the browser phoning home constantly, they know which account to associate your browsing behavior with, no account creation required ;)
So where to go? At the moment I'm happy with my Waterfox. And there's the somewhat similar Basilisk-project from the Pale Moon camp. But I realize these are overwhelmingly likely to be dead ends in the slightly longer run. There'll come a day when recent uMatrix et alia will no longer work. And a day when the dev-teams themselves throw in their towels.
The FF57-thing is just depressing in its own right, even without this added round of Mozila idiocy. They couldn't offer us just the option of an extra toolbar, or any customization worth the name, really. Firefox of ten years ago had vastly better UI than this latest, dumbed-down iteration.
But I suspect I shall sooner or later have to return.
[Edit: typo]