I've been using web browsers, the kind you run on regular ol' computers, for... 29 and a half years? Let's call it 30. So forgive me if I think it's worth writing about when I switch to a new one. I switched my default from Firefox to Arc a couple weeks ago. I have some thoughts about it!
The first thing I have to correct for: I'm sure that fully half of what I'm enjoying is the novelty of it. Shiny new interface, and even just faint threats of new ways to drive around on the internet? Fuhgeddaboutit! My ADHD is fully powered and sparking with energy. Combine this with my recently-rekindled web development fervor and we're at least possibly in full midlife-crisis mode here, but it's still possible to try and take a hard look at what's up.
Tabs and spaces and favorites, oh my: while it's sometimes disorienting to have one's tabs on the left rather than across the top, what's really head-twisty about Arc for me is that there aren't bookmarks the way I'm used to; there are just different varieties of tabs. Most people are apparently not bookmark users anyway, and prefer to rack up tabs, so why not pave the cowpaths, I suppose. This hasn't caused any real trouble for me apart from occasional momentary confusion, though - all my Firefox bookmarks are sitting here in a folder, in what Arc calls the pinned-tabs section. If you're highly concerned with a tab and think it's a keeper, you'll want to drag it "above the fold" into the pinned tabs for a given workspace (that's another thing - Arc favors these "spaces" instead of making new windows for everything, and you can associate them with conventional browser profiles if you want). If you leave a tab down in the dross, it might get cleaned up for you, which means spelunking into the archived tabs, which is easy enough but induces a little anxiety.
There are also the favorites, which are big ol' buttons you can make at the top of the sidebar. These don't create a new tab the way I keep expecting, but will open an existing one if it's still in memory... yet not particularly represented on screen in any way. This induces a little anxiety too, but it also just works the way I want, pretty much all the time, so I'm letting it ride. (This is reminding me of how Beaker impressed me just as much with its general completeness and absence of annoyingly unsupported things as it did with its new features. This might mostly just come with the territory of embedding WebKit, although one should note that Arc is not an Electron app, but is written in native Swift and feels that way: snappy and clean.)
Belly up to the bar: the URL bar is... not entirely gone, but mostly you interact with this popup thing that'll remind you of Spotlight, or other sorts of launcher utilities. This thing, that also manifests when you ask for a new tab with the familiar
command-T, offers the usual URL-bar options plus a bunch of built-in commands and shortcuts - things like Open Downloads or New Google Doc and such. This is hot, hot, hot and puts me in mind of my beloved late launcher Enso and its in-browser progeny Ubiquity. Make these commands a thing we can write as extensions, BCNY!
(On the subject of extensions, though: Arc calls these Boosts, which is apparently supposed to reflect their nature of boosting the functionality of specific sites, or of sites in general but by means of injection into the page. They're just Chrome extensions, written to the same APIs and linking to the same help docs. But Arc seems to cut out the popup-menu-ish extensions that I think are the most popular, and that would be a natural fit to sit amongst the favorites buttons. Just in general, Boosts feel underbaked, despite the relatively elaborate UI that's been built out for them.)
The extra jazz: Notes and Easels. Notes amount to a no-op at this stage; they're a text editor in your browser, and that's kind of it. That's not nothing, and there is some sharing functionality I don't understand which is probably aimed at blogging-or-something at some point in the future - all to the good, but nothing that's really there yet. Easels are more interesting, albeit more problematic.
Easels are virtual scrapbook pages. You can type in some fun fonts, do little doodles... but the point is they're tightly coupled with capturing, which is just a screenshot of a portion of a page. That is, they're screenshots until you click the little Play button to make them... live? Yep, they turn into little frame displays of a live page, which is cool and has fascinating possibilities for dashboards and such. I'm concerned about how there's no view-source option for easels. There's no capacity to edit them outside of Arc itself, perhaps because you can open them to editing by others ("anyone"!?!??!), indicating they might be meant as part of the eventual "multiplayer" feature that BCNY has mentioned as a possible business model.
Last but a long way from least is the audio and video functionality. As someone who makes much more use of YouTube and Twitch than a middle-aged man perhaps ought, this has been the single biggest win of my time with Arc. When you play video or sound, then go to another tab, the video pops up in a mini-window that's resizable and quite full-featured; audio-only media will get you a little mini-controller at the bottom of the sidebar. Both are super handy! The only note I have is it would be cool if the video player also popped up when you switch away from Arc entirely, although I'd wager it's impossible to tell when the frontmost tab is covered up visually.
The future: BCNY is venture-backed, and it's reasonable to be suspicious of any commercial venture that has a closed-source browser for you to download. There is such a strong need for UI innovation in browsers that they have me excited, but they sometimes don't seem aware of currents of thought along those lines that one would hope they'd be. For example, they don't have a fediverse account, and don't generally show evidence that they understand the history of efforts to make the web into the internet computer they claim to want. I sometimes worry that this vision of such a device is not coming from internet people.
I'm talking about feeds. Some capacity to do what RSS readers did, and probably what social media clients do, belongs in browsers. Browsers have already circled back to one of the major purposes people went to feeds for - readability - and made it a feature on its own (Arc's readability mode is allegedly present, but hidden and buggy); the other major purpose of feeds, that of catching updates, avails itself of all sorts of approaches. Imagine a browser that had configurable means of checking a URL in the background and letting you know if something interesting (the meaning of "interesting" being something you specify) has changed since the last check. Maybe it has custom tooling for, ahem, certain websites from which people often wish to see the latest.
I'm honestly not sure whether that's a bigger or smaller feature than just building a damn feed reader into the browser, which has still never been tried apart from that one awful half-assed one that Firefox made back in the day. And I understand the reluctance to give people another inbox they have to check. But giving us all the opportunity to say for ourselves what "follow" means would be halfway to the information revolution of which Arc has been waving the flag. I know y'all know what a memex is, BCNY; now show us.