I tried to like the new Firefox, maybe I didn't give it a fair chance, but it instantly disappointed me.I opened 5 gifs in new tabs and CPU usage rushed to 100% an all cores for half a minute.
But often it's the small things that make or break it. For me it was that HTML5 videos don't fullscreen to a new workspace on macOS like they do in Chrome or Safari.
If it still happens and you want to dig into it a little further the profiler at http://perf-html.io/ allows you to gather and dig into + share details that can help fix.
But often it's the small things that make or break it. For me it was that HTML5 videos don't fullscreen to a new workspace on macOS like they do in Chrome or Safari.