Difference between doing network calls using RxJava+Retrofit vs Robospice+Retrofit

Question

I used to do network calls using robospice + retrofit, but I recently I came to know we can do same using rxjava and retrofit

Same example

using rxjava and retrofit, http://randomdotnext.com/retrofit-rxjava/

Using Robospoice and retrofit https://github.com/octo-online/RoboSpice-samples/tree/release/robospice-sample-retrofit

May I know pro and cons of them, Thank you!