I've yet to see anything that's causing me to complain.
I'm running it on openSuse Tumbleweed (Linux), as a Flatpak.
Granted, Opera is one of four browsers that I actively use, and I use it about 10-20% of my total browser time.
And I only use it for "minor" stuff, like checking on various forums. Also, I don't have all the fancy features and crazy UI stuff enabled.
However, and don't get me rwong - I see all the complaints out here (I've assisted with some), so I know there are MANY issues. Anyway, I'm not here to thumbs up, but I'm shocked at all the issues - issues I don't experience. Maybe 'cause I'm on Linux