I'm not trying to troll but why do you actually use Opera on Windows?
Because its the better browser without any bloatware and can do almost everything without requiring further extensions like firefox and has no privacy issues like chrome - besides the RAM and CPU usage is way below - point is its the only modern browser you can still use on a Pentium 100.
If you ignore all that, it comes down to personal taste i guess. However most things you take for granted in your browser were actually invented first for opera and then copied (tabs, paste+go, speedwheel etc)