Like all frameworks, it has its pro's and con's. You would be mad to write a serious game or a heavy app with this. But we have built simple games using this. Performance is probably much better can you expect.

The biggest problem we see is one constantly needs to figure out workarounds for annoying platform specific bugs. One that is driving us nuts now is playing sound on Android. And this is connected to the fact that the time saved on making a single codebase is usually wasted on trying to figure out these workarounds.

The biggest pro is - yes, you can build an app in Javascript and it will work on Android and iOS. If you only know JS, then you can expand on your offerings. There are a bunch libraries that make life easy - ionic for example for UI stuff.

For the right app (small; simple) then its a good option. But be prepared to swear a lot :)

Been doing Cordova + Polymer. Works well and looks like a native app. Still think you need to have a decent knowledge of your target platforms for fixing issues like FB integration.