[stupidcar]

I think this had to more to do with internal pressures at Google than the actual state of the code. They had been working on it for a long time, and, I think were under some pressure to actually ship something. Angular v4 is what the first production version should have looked like.

Having just upgraded a large AngularJS v1 project to Angular v4, I'm actually very happy with where it's ended up. It feels like a very good combination of power and flexibility. There are still some complex bits, but it feels more like the complexity is necessary and sanely designed, rather than the craziness of what AngularJS's directive stuff evolved into.

[growtofill]

Would you share some stats about the upgrade? How many LoCs was the codebase and how many man/hours it took?

[camus2]

s/upgrade/rewrite . I don't believe a second there is a reasonable way to upgrade 1.X from 4.X without rewriting all UI related code.