I'd recommend it if you need to make an angular app look and behave like a native app as much as possible.
Unfortunately if you want to deviate from ionic's currently small pool of iOS-ish design metaphors, then it's not flexible at all, that's what you sacrifice for having everything else work with minimum fuss. I believe they are working on remedying this, there's lots of stuff on the issue tracker about enabling iOS Mail style layouts and so on.
In the end, it's just angular, and ui-router: this is its strength. Take a look at the repo.