[cobar]

Development time is a lot quicker with RN. Not only are you targeting a single code base instead of maintaining two apps, but the React environment helps you to be productive.

The React way of managing views makes a lot of sense - change a variable and the whole UI updates accordingly. Also, rather than going through the typical debug, modify code, recompile cycle, there is a Hot Reload mode in RN where your code updates are immediately applied when you save. Laying the UI out with RN's CSS-style syntax is a lot easier than doing it by hand or mucking with Interface Builder / Android XML files. There is a lot that RN wraps around that gives easier management of than the native approach to, e.g. a BackButton component vs. dealing with a stack of Android fragments.

I haven't done any PhoneGap programming, the lack of native UI always scared me off. Without that, I never felt like I could hit a level of polish that was acceptable. The nice thing with RN is you can build you own native components and access native functionality as needed. It's not super well documented, but powerful when you need it.