I started giving a try to Zen (based on firefox) a few days ago. I like it especially while heavily relying on a tiling window manager.
I daily drove Zen for months. The design and implementation are overall fantastic. Unfortunately it still has chronic performance issues, gobbling up CPU randomly - and they don't seem to be too focused on despite it being a commonly reported issue.
I don't want to burn out my battery quicker than usual, so I was forced to switch off. I'm currently trying Orion instead and have been loving it - aside from several poorly implemented websites just not working on it. And the Cloudflare false positives, but that's as much or more an issue on Zen.
Agree with sibling comment as someone who used Zen for many months, maybe as long as a year or two. It constantly breaks and often stays broken in small but fundamentally important ways, to the point that I just switched back to FF last week and am glad to be off the roller coaster. Before Zen I had tried Arc and left for a lot of the same reasons.
For all of the (valid) criticism against FF, it's still the best available browser that's not just an experiment IMHO.
Edit to add: part of the switch back is that FF now supports, to some degree, all the features I was using Zen for: vertical tabs (needs customization but works well enough), custom search "engines" (ie, shortcuts), split view, not-Chrome