Exactly, too! I began using Opera back in the version 3 days (3.12?)--paid for both the Windows version and, when it later came out, the Linux version. (Version 3 supported server-push, so I could monitor our system using a homebrew embedded web server that pushed out updated indicators.) Hung on to version 11.64 as long as I could (version 12 had some problem or another for me), but finally switched to PaleMoon a year or two ago.
In the latter years, what I really liked about Opera were, aside from its speed, (1) the bookmarking system and (2) middle-clicking on a link to open up and transfer focus to a new tab. I've tried Vivaldi and Otter, but neither one was close to the classic Opera experience. No other browser I've tried has matched the ease of use of classic Opera's bookmarking system. PaleMoon (and, I guess, Firefox) is not bad in this regard, but still a little clunky.
Sour grapes warning (!): Regarding middle-clicking on a link, apparently I'm in a minority; Chrome made a conscious choice to open up tabs in the background because users preferred reading an article all the way through, clicking on the links as they go, and then looking at the linked sites. (I know there is a Chrome add-on that adds this functionality, but there are other reasons Chrome is an awkward browser for me.) PaleMoon largely gets this right for me except in the case when I right-click to Google the highlighted text and the Google results tab is in the background.