I gotta give this one to @Vivaldi for sure.
Just had a very annoying (but great for testing) situation where I have a long-running job to copy data between two tabs, and then a different two tabs needed to be updated after each time the first two tabs were changed.
So I opened Vivaldi for it. Put all four tabs in a stack, and then tiled each of the first two and the other two tabs.
Such a minor thing but it really did make a difference to how smooth the whole boring job felt. The tiling is implemented really well too, very intuitive going back and forth between the two sets of tiled tabs. Very cool built-in feature.