Long time user (15-20 yrs?), I have been avoiding the "next" upgrade for several years for various reasons (hate change, fave add-ons go away, hate change, not broke-don't fix, hate change...). But I am now running into a few websites that won't permit this browser, so it may be time to move on. With heavy adblocking and tracker-blocking and my benign web browsing habits, I've not been concerned about security (never had a virus in 20 years - knock wood). It's just full functionality and slowness at this point. At this point, I see even my Classic Theme Restorer is no longer available, so I'll just have to bite the bullet on aesthetics and deal with a modern browser. However, a couple of things are unclear: 1. does 20 years of bookmark history (and remembered history) affect memory footprint. I only refer to existing bookmarks occasionally these days and may consider a full purge. Partial purge would probably be too time-consuming. Maybe even a full profile purge might be worthwhile for a true clean slate. Maybe FF has come a long way and old extensions and settings won't be necessary. I also have several about: settings that I may (or may not?) miss. 2. Are automatic updates unavoidable in newer versions? I read about "manual" but it sounded temporary. 3. The permissions on many potential add-ons I've looked at are quite unnerving... e.g many of them require full access to ALL my data (usernames and passwords!!!) and I know the function has no need for such. Who has time to investigate these fully for safety? Is there any anti-malware vetting required for add-ons to be available? 4. I know newer is generally faster, but FF has a history of growing and slowing down after upgrades. My hardware isn't getting any newer (although its more than ample for my current needs), but software tends to be developed on latest and greatest hardware. How does latest FF compare to circa V41 in memory usage? In any case, I thought I would give the latest vesion a whirl on my old Vista laptop (which is currently at V43) and check it out before plunging in on my W7 work PC or home PC. Any answers or insight into such a big jump are much appreciated.