They actually did, the recent switch to multiprocessing made a massive difference. I've been happily using Vivaldi for a few months now, but I'm tempted to go back to FF as the speed gap has been wiped out of late - only cold startups are a bit slower, actual pageload is absolutely on par or better. This on Mac, at least, but I expect it will have been similar on other platforms.
Last time I tried it still was slow... I'll give it another try.
Yeah, a lot has happened in the past few months. And there's still more things scheduled for the next few versions...
When was the last time you tried? R55 is way snappier than Chrome. Nightly is also fast.