Arc is good. There’s plenty to like, and has lasting potential.

That being said, here’s some recent copy pasta from another comment I wrote. It highlights reasons I’ve started looking back at FF (or Safari).

—— I've been using Arc for a couple of months now. But lately I've been toying with the idea of going back. Why?

• Extensions. I really, really, really wish I could see my password manager in plain view. Arc has a problem of limited screen real estate; instead of showing extensions, they choose to show buttons for spaces (and big buttons for "Favorites").
• Tab sync. It's not super confusing, but it's a little confusing, having pinned tabs sync but other tabs not sync. Especially when Arc is going to auto-archive tabs for me. It creates a chaotic experience.

Things I'll miss if I go back!

• Little Arc. I love it. It's quick and what I need often times, for both in-page links and .webloc files I have in various places. The only problem Little Arc has is it is single-instanced; that makes it hard to use as my solution for PWA shortcuts on the desktop.
• Mobile Arc. It's a neat way to implement mobile. I dig it.

Things that didn't matter too much, but I'll call out:

• I miss having a downloads button easily view- and click-able. Why? I like to see progress % and speed at a glance.
• The window borders are thicc. I used to change Windows registry settings to have thin window borders.
• The "add split" buttons at the top right are too easy to click on, and accidentally splitting a window can kill your progress in a web form.
• Settings don't sync between instances. This sucks for me because I manually remap Ctrl+Tab / Ctrl+Shift+Tab to sequential switching rather than "last used", and I have to manually remap that on all my Arc installs. [Same with Bitwarden’s field-fill shortcut.]

I’m a Firefox user trying out Orion right now. I gotta say that I’m impressed. It looks and acts like Safari, which I like, but supports all the extensions I love.