Here's why I went back to 1Password 7

Can echo a lot of the comments in here and add a few more. Similar extremely long-time 1Password user across multiple platforms.

The new browser auto-fill is sluggish, unreliable, and intrusive, particularly on less reliable internet. Among several other things, it appears that the icons are not cached locally on the device any longer, or at least the caching itself seems unreliable when the network is slow, meaning that you often get blank pop ups while the information loads. Honestly, I would prefer to disable the popups altogether and just rely on Cmd-\. It also doesn't help that the popups block UI elements (e.g. submit buttons!) and are beyond useless during signup flows.

The use of the accessibility toolkit to auto-fill is a significant regression in and of itself. It is massively slower and a much worse experience overall, particularly since it actually "types" the password. Particularly for longer passwords, this results in a very meaningful delay where you need to just wait before form submission. Additionally, the time between pressing Cmd-\ and when the autofill actually happens, even when 1Password is already unlocked, is at least triple what it was in 1P 7.

Universal autofill is not particularly useful. I found it helpful exactly once: when logging into the Discord application. Every other time I've tried to use it, the autofill has picked the wrong thing to fill and it has been problematic. This is particularly bad in the Terminal, where password prompts are masked, so I have no idea that it has typed the wrong thing until it submits. In practice, I'm just using the universal search the same way I did before with 1P Mini, at which point everything about it is either equal or strictly worse than before.

Auto-Fill behaves quite badly if 1Password isn't open. If the app itself isn't open, pressing the autofill keybind will actually pass all the way through to the underlying application. For example, I use Cmd-Shift-\ for autofill, and when I use this in Safari and the 1Password app was closed, it will zoom out to the tabs management screen. This is made much worse by the fact that the app seems to auto close sometimes for reasons I haven't fully determined, which is another problem I never had with any previous version.

The UI really doesn't look very good. The more native look and feel of the previous generations of applications was much, much better. Design has always been a strength of 1Password and it's really surprising to see this magnitude of regression in such a core area. It's not the worst thing, but the reduction in contrast across the board has not done any favors. Also the new New Item flow is markedly slower for users who already understand what they want to do (in most cases, add a Login). Additionally, the new UX is extremely sluggish compared to the old implementation, likely due to the fact that it is no longer a native application.

The security implications of this are… not great. Not only are you asking me to trust a JavaScript based implementation of the most security-sensitive application on my machine, but you are also asking me to give it access to the most intrusive and sensitive system control feature (Accessibility). The vulnerability surface area has expanded from a keyhole to a vast chasm, and I don't understand why this doesn't disconcert everyone.

All in all, if 1Password 8 were the current version and 1Password 7 were released today, it would be received as a significant upgrade from 8 in nearly every meaningful respect. In fact, swapping back to 1Password 7 today after having used 8 for about two weeks, I can say that it feels like a dramatic breath of fresh air in every respect.