Almost looks promising... has anybody used it?

Building right now with it several apps (even with webrtc). If you're a webdev (js/angular, css/sass, etc), it's a god-sent solution... The key is adding chromium (crosswalk) in order to get a consistent experience across android devices. iOS does ok...

https://crosswalk-project.org/

Are you using Crosswalk for both iOS and Android, or just for Android? We've been using Ionic + Cordova with pretty good results on iOS so far, but we're starting to shift focus onto the Android offering.

Only for Android. iOS' webview is powerful enough for our use cases, and if you need webrtc there are a couple of good cordova plugins.

I've been using it for the past couple months and it is hands-down the best option for hybrid mobile development

I used it for a fairly complex application for Georgia Tech's classroom manager. It worked really well -- notifications, insane authentication and WebView stuff. On Android, speed was an issue on older versions until I used Crosswalk. However, Crosswalk would crash on older phones :/ Development and debugging Ionic was really easy.

Yes, I used it to create one of my apps. Very satisfied by the feature set provided by them. Very excited about the new changes they will be rolling out from beta soon.

Yep. I've built several things in it. It's very good.