Really? Huh. I only stuck with it as a daily driver for maybe a couple of months just before FF rolled out vertical tabs, but it was quite rough for me.

Same. I've been using it daily for the best part of a year and it's been pretty pleasant to use throughout.

Because web content is increasingly mobile and vertical-oriented. So the horizontal space is usually empty anyway.

Sometimes new things take time to get used to but if you try it for more than a single day you may find that you like it.

because when you have more than 8 tabs open on a horizontal tab row, the tab handles start to become narrower and tab titles become unreadable and almost useless. with vertical tabs tab titles can be as long as you see fit, and the tab title does not take away space from other tab handles so more can fit. essentially its more space efficient I think.

but I don't use it because my firefox theme breaks down when I set up vertical tabs, and everything will be white, even though I don't even use userchrome customizations

I prefer the overview I get with them. I’m on an ultrawide monitor so it’s not like I’m sacrificing horizontal space either.

You absolutely do have pinned tabs on FF. They go double column when you shrink down the sidebar, too, which I like. And they work with tab groups. Can't believe those took so long to steal from Chrome. Did support for groups get integrated into Zen as well? That's probably my line in the sand these days.

I was interested in the Glance concept, but I did not love the implementation. It was hard to tell when you were inside a Glance tab and I ended up struggling to deploy those into a persistent tab if I wanted to keep them for later. The idea was intriguing, but I never clicked with the details of the UX. It always took a little bit more thinking to work around than just... right clicking into new tab, I guess.

You should try the Shimmer userchrome tweaks along with the Sideberry extension. With both of them it's even better than Zen IMO.

You can set them up so they only deploy when tapping the sidebar icon and stay hidden otherwise, which is my compromise for that. I thought it'd take me longer to adapt to that when moving back from Zen, but since the top bar does deploy on proximity when using fullscreen I find it's pretty intuitive to deploy and hide them both on mouse and touch, and I have to admit that not having them deploy accidentally when hidden is actually nice.

I do like the vertical tab pins better on Firefox, and with the new tab grouping being supported on vertical tabs I am quite happy with the setup. It takes longer to set up the way I want it compared to Zen, but honestly, I'm quite happy with it now. I'd have considered going back because more alternatives is better, but frankly Zen just had too many significant bugs in my time with it, and since it doesn't just use the engine, but it's also hooked up to Firefox's account system for a bunch of stuff it just didn't seem worth the hassle. Have they polished it up any in the past few months?

Hah. Well, that and a good fullscreen browser for OLED displays were my main motivations. Both of those are addressed by FF now.

Also, the vertical bar can be set to whatever width you want on both, I think. On FF (which is what I'm typing this in, so I can check) you can shrink it down so it only displays a single row of icons.

The idea is to hide it altogether when you're not using it, in any case, but you can definitely make it as skinny or skinnier than tthe top bar.