Pretty impressive work coming out of AgileBits. 1Password X isn't for me, because I like the current arrangement of a desktop application integrating with the browser. I don't think I'm ready for direct browser to service password management even from one of the companies I trust the most.
1Password X is a radical new way of using 1Password, but it’s not (yet) for everyone. It’s still in its early stages so some features are not yet available. For example, it’s not yet possible to customize generated passwords or use browsers like Safari, Firefox, and Edge.
This had to be a huge amount of work to get right. I'm sure the Linux folks will give it an intense workout so maybe some day it'll be in my browser too.
As a side note, I'm betting AgileBits named it "1Password X" before the iPhone X was announced. What a bummer for them that they have to explain that it's not pronounced "ten."