Check out Vivaldi: https://vivaldi.com/
I've been VERY pleased with it so far, under Windows, OS X and Linux..
It has the one thing that I missed most from the old Opera: Sane/useful tab stacking/grouping built in, with the ability to save and restore such.
Sure, many of you don't care about that, but I do.
At work with the old Opera, I'd create sets of tabs, stacked as I saw fit, for each client and would then save them as profiles named for my clients.
When I got a support call all I had to do was open the saved tab profile for them, and then I'd have EVERYTHING related to them available to me immediately, organized in the way I found most useful to me.
Yes, it took time to set that all up. Yes, it took time to maintain it, but all that time paid for itself, every time I fielded a service call for my customers.
It was an amazingly powerful tool for me, and when Opera dropped it I stayed with the old version until it didn't work anymore.
I looked for similar functionality under Chrome, et al, Firefox and IE but nothing came close.
Vivaldi gave that back to me, and I've switched and will never go back.
It's still very "young", and they are working hard on it. But, they appear to be very motivated and committed.
The current stable release is great, does everything I need, and even better? Since it's multi-platform I get the same basic experience and usability regardless of OS.
While I still use mostly Windows at home, I support Windows, OS X and Linux at work now, and having a web browser that works under all three with the functionality that I want/need allows me to support our users, regardless of OS, without having to switch back and forth between computers
And to bring this back on-topic? Vivaldi is built upon Chromium and still supports the backspace key for going back a page.
The only thing I wish they'd add? Native proxy support, such as Firefox does. I've used Privoxy: http://www.privoxy.org/
under Windows for years, and, while the old Opera had its own proxy support, just as Firefox does? Vivaldi doesn't yet, so I have to resort to an add-on for that, since some of the games that I play at home don't support proxies.
Take all of the above for whatever it's worth to you, but I think that Vivaldi is at least worth checking out.