Compare Content REST Service with Rhythmyx Web Services Development Kit

Percussion tech support told me that "The ContentRS project is not a Percussion product. It was created by PSO and is community supported via the forums, provided as is, and is available on http://code.percussion.com/svn/." Tech support also suggests redirecting the support ticket to the forums and hope someone in PSO will answer the questions there.

I want to get some authoritative comparison of the two ways of reading/creating/deleting/modifying/… CMS content items: Content REST service and regular web services? scenarios on when to use which?

We heavily depend on the DEV CMS server. Are there any side effects to the underlying CMS servers if Content REST Service is installed? I do NOT see any myself, but want to get authoritative confirmation from Percussion

Are there any documentation on using the Content REST Service? example code and explanation? In the example form for calling Rest Service: http://code.percussion.com/svn/ContentREST/trunk/WEB-INF/importtest_post.jsp, what should be put in the Feed URL?

Thanks, Hua