What's up with AngularJS?

I've been thinking about looking into Angular for a while now. I know a few people who swear by it, but, coincidentally, they're all backend developers (PHP/Symfony2). I actually do not know any frontend developers who actively use Angular. It's curious that this seems to be exactly the same situation that prompted ppk to write a rather lengthy opinion piece about Angular (well worth a read, I think, even if your mileage may vary). In fact, he felt compelled to say that "If one is uncharitably inclined, one could describe it as a front-end framework by non-front-enders for non-front-enders" about Angular 1.x’s suitability for modern web development.

I would love to hear about lessons learned and a few personal impressions to gain a broader view. Are the mentioned performance issues as severe as indicated? Is it really that mobile-unfriendly? Please do share your experiences @polarbirke.

Update January 15: ppk reacted to the huge amount of feedback with a follow-up article about his reservations regarding AngularJS.

Update January 30: Jeremy Keith also chimed in with his column about Angular Momentum.