My Firefox briefly updated too, but I soon discovered that my most important add-on was much worse than before so I downgraded back to version 56. Unfortunately now all my site icons have gone grey.
Anyway, during the very short period of time that I used the new version it seemed very quick.

Regarding that warning message, I always ignore it and TalJehin is right, you can hardly mess anything up by changing a couple of minor settings.

Michael Ayton wrote on 11/18/17 at 12:48:44:

Thanks JEH, that's useful info. My DL and UL speeds seem OK (4.9/0.8) so maybe it's memory? -- seems I've used '1.3 of [only!] 2.7 GB'.

Is anyone using the new Firefox browser update (the one with the blue strip at the top), and if so, are you finding it as slow and laggy as I am? Scroll bar on the right is sticking, and loading and closing pages can be slow. I even had to type this in another program and import it since typing it in situ using Firefox was so slow.

I don’t get these issues with Chrome or Edge, nor really did I (at least nowhere near so much) with the older Firefox. Does this suggest a memory issue? I looked at a couple of Firefox help pages (https://support.mozilla.org/en-US/questions/981140; https://support.mozilla.org/en-US/questions/1157085), but typing ‘about:config’ in the URL omnibox I get a ‘Do you know what you’re doing?’-style warning message so am reluctant to proceed. Refreshing makes no difference, nor does whether I enable AdBlock or not. Anyone got any thoughts?