Client Server approach for Android application

I currently have a working implementation using GAE and servlets to communicate with my android application. The app will create json objects and send/receive them using the httpclient. I then was looking at the 2.4 beta plugin for using C2DM and noticed that they use GWT along with a RequestFactory for communication. I was wondering i开发者_如何学Cf this approach is worth the time switching? Is it easy to setup and configure? Seems like this would be a nice approach if i want to say develop a mobile site along with the app?

If you use C2DM you will need your users to use a google account. I personally don't feel 100% confortable with that.

The best thing about C2DM is that you avoid polling your GAE server. If you have an already working solution, why would you change it?

I would recommend android - appengine combination. However if you want your app to be on non google-play device, you need to think around C2DM/LVL or google wallet API(a mandatory on google play). RequestFactory is great but it is tightly coupled, imho. I would recommend Rest which is platform agnostic, very loosely coupled, thus support GWT, android, iOS, BlackBerry, WebOS, desktop ...