It seems to have gone on latest update, because I can't find it.
I have latest stable version and OS is Linux Ubuntu.

I wish we could have ability to report broken sites or at least, bring back old 'mask browser as Firefox'-ability.
(Sorry, English is not my first language.)

You find it from "settings". (second subpage from top, first being 'Browser'. I don't use English version of Opera, sorry.)

• Ask before closing (I close my browser way too often without meaning to do so.)

• Enable/Disable redirecting (all and site-by-site-basis) as was on Presto.

Nice to know this will be fixed in next update. I use pdf:s lot.(horse racing)

I thank you for your kind answer.

...Maybe I just used Presto-based Opera for too long.

I don't really care about Notes, Irc/mail nor sidebar, but missing those two things that I mentioned in first post make me feel I'm walking in otherwise lovely shoes that are two numbers too small.

I've tried this "new" Opera for few days.
Two things that were silently dropped in new (but were important for me in 12.xx) presented themselves rather quickly.

*Since you can't no longer resize tabs you're forced to open different windows and resize them. (Ie. having game and chat window of game side-by-side, risking accidental closing.)

*Thing that made Opera first-of-its-kind, 'ask before closing' has been dropped. (It made me love Opera even more.) My question: Why?