Firefox very slug after update to 96.0, 96.01 slihtly better but still sluggish
After updating to Firefox 96.0, Firefox became unusable. Went from happily playing two youtube tabs (one speech, other background music) 2 tabs in separate windows of 10 to 12 windows open with more than 10 tabs in each window, although many were inactive, alongside Apple Mail and often one or two other apps open such as Preview, VLC or TextEdit; whereas immediately after update to Firefox 96.0 to taking 10 minutes to load a tab when only 2 or 3 tabs were open, and unable to play youtube videos without continuous breaks totalling far more than the video itself, and unable to play embedded videos in BBC news website when only 2 or 3 tabs open in one window with no other apps running, other apps were very sluggish when Firefox running; all other apps ran fine, as normal when Firefox was not running.
Firefox 96.0.1 improved it's ability. Youtube videos will mostly play now if there is only 2 or 3 tabs open, as with BBC embedded videos, tabs are often now taking 3 to 5 minutes to load.
Downloads were like night & day, Firefox was happily working until updated to FF 96, immediately after update FF was almost impossible to use, updating to 96.0.1 created a little more usability, but still cumbersome and very sluggish to the point of pretty well unusable. Was running FF on 2011 Mac Mini, OS 10.12.6 with 16GB RAM