I'll be looking to downgrade to Firefox Extended Support Release 52.4.1 [1] and using the hidden settings to enable Electrolysis [2]. Currently on 56 and it's very fast but with 57 tabs mix plus is gone [3]. [1] https://www.mozilla.org/en-US/firefox/organizations/all/#en-... [2] https://fossbytes.com/how-to-make-firefox-faster-by-enabling... [3] https://addons.mozilla.org/en-US/firefox/addon/tab-mix-plus/
I will be doing the same. The enhancements in 57 don't out-weight the productivity loss from my critical extensions. I'll be waiting until more of them are ported forward. For the record I don't actually find Firefox 56 slow at the moment either.
Shoving webextensions down everyone's throat, and only afterwards starting to work on implementing APIs and giving anyone a chance to start working on porting stuff. No thanks.