Yep. I rarely see Firefox lagging/unresponsive (~15 pinned + 3-4 normal tabs open). In the rare chances that it does, I get an option "This web page is slowing

Yep. I rarely see Firefox lagging/unresponsive (~15 pinned + 3-4 normal tabs open). In the rare chances that it does, I get an option "This web page is slowing down Firefox" which lets me kill the tab and all is well again.