After about a week of tweaking and testing in Android and iOS, here is what I am planning to release my next app with:
CocoonJS - Allows Admob ads, but has an annoying flickering splash screen, and has a very primitive scaling system that doesn't center the layout on the device screen, and shows a lot of offscreen content.
Ejecta - Allows only iAds, but automatically centers the canvas. In addition, you have complete control over the project in xcode, which means it is very simple to replace the Ejecta splash screen with your own.
Results for iOS - Though Admob support is nice, Ejecta wins by creating a more professional-looking end product.
CocoonJS - Same strengths and weaknesses as iOS export.
Crosswalk - Allows much greater control over the device, but has two major drawbacks: 1. Doesn't allow Admob ads 2. Support/internal web links are handled by the "in-app browser", which looks very unprofessional. I can't for the life of me get anything to open in an external browser.
Results for Android - I so wanted to go with Crosswalk because the CocoonJS splash looks awful, but the inability to open an external browser and the inability to use Admob killed Crosswalk for me.
For my next app:
iOS - Ejecta
Android - CocoonJS