I think it's just that the UI feels laggy when switching tabs, especially if another page is loading. This might be getting better, though: today I just randoml

I think it's just that the UI feels laggy when switching tabs, especially if another page is loading. This might be getting better, though: today I just randomly stumbled on this Mozilla wiki page discussing their plan for dealing with this UI lag: increasing the number of content threads. https://wiki.mozilla.org/Electrolysis/Multiple_content_processes https://wiki.mozilla.org/Electrolysis/Multiple_content_proce... The setting defaults to 1, but will be moving to 2, and then 5 eventually. I'm testing Firefox Developer Edition 51.0a2 (2016-09-26) with this set at 4 right now. I only ever have ~10 tabs open, uBlock Origin + Privacy Badger addon, and my machine is fast and has lots of RAM.