Pro Upgrade Path and Governance
If you are an engineering leader that intends to build a lasting project for the web, Ember should be high on your list. No other web/js framework has followed a consistent upgrade path, allowing incremental, in-place updates. Companies like intercom have apps that are current with the latest version, having lived in place without a re-write for up to eight years!
Pro Opinionated in terms of application structure
Ember already defines the general application structure and organization for you. This was done to prevent developers from making mistakes which would needlessly over-complicate their application. While it's still possible to go out of these practices forced to developers by the Ember authors, you still have to go out of your way to force them.