If this was the only feature FF has ever shoved down my throat I would be fine with it, but without the disabling the feature recommendation option, every other time I open a tab I get hit with a pop-up for some minor UI change. The worst part is that it stops typing so sometimes I was just typing into the abyss for 5 minutes before I realize it lost everything I typed.
I've been using since 3 and I don't think it's a miracle browser or anything. Anecdotally I've observed plenty of folks try FF for bit in the wake of Manifest v3 then switch to Edge/Brave, and it's not because of a lack of AI. They need this sidebar but it's not the only reason they're losing.