Approach to fetch information from RTC: Java API vs Reportable REST API vs OSLC

Hi,

I need to fetch information like story points, builds info etc. from RTC. I would like to which approach would be better to use among the following available approaches - Java APIs, Reportable REST APIs and OSLC and why?

I heard that Reportable REST and OSLC APIs are slow and have some performance concerns. Also, Reportable REST only supports XML (not JSON).

Any information regarding this would be very appreciated.

Thanks,

Yogesh