I am guessing from the documentation that the new RMA has five major features.
 
1.  It is easy to enter a disposition and reason codes.
2.  Creation of a repair order is simple and does not pull in standard price  
3.  During normal flow there are two screens. The screens allow easy entry, tracking, and printing of returned goods.
4.  There is a special, faster way of Recieving Returned Items  
5.  Putting repaired items back in stock does not throw off the way we track production costs.
 
Is there an overview, procedure, or brochure somewhere?    When I say to people use the module because it is 'integrated better' they frown and look at each other.  

Well, as we recently learned, all of your points PLUS the fact that if you use the old RMA system, you absolutely cannot run Crystal Reports to track reasons for RMAs.  The data is not traditionally stored, and you have to extract it out and into a spreadsheet, and even then you really can't create the kind of reports you need.  BUT, if you use the new module, you can in fact create and use Crystal reports to track the information better.  You can also control the reasons why the RMA was created.  We discovered that things were "all across the board" for reasons--not very much consistency, even though we have published standard reasons that were supposed to be used--not to mention the misspellings in the reasons!  Using the  new module will help keep the data cleaner and standardized.  That is really important.
 
Val