Looking for insight into the differences without getting the source code.    I currently using umbracoExamine.Contrib to search for FileTextContent (.pdf docs) and it seems to combine all other data such as bodyText and my custom user fields.  Below is my filter code and my IndexSet.  Just looking for best practices.  Also in the future if I need to search against .docx, .txt what would be the best way?

Thanks!

Jason

var criteria = ExamineManager.Instance.SearchProviderCollection["ContentAndPDFSearcher"].CreateSearchCriteria(BooleanOperation.Or);

var filter = criteria.GroupedOr(new string[] { "nodeName", "bodyText", "FileTextContent", "productTitle" }, SearchTerm)
                                .Not()
                                .Field("umbracoNaviHide", "1")
                                .Compile();

<IndexSet SetName="ContentAndPDFIndexSet" IndexPath="~/App_Data/TEMP/ExamineIndexes/ContentAndPDFIndexSet/">
    <IndexAttributeFields>
      <add Name="id" />
      <add Name="nodeName"/>
      <add Name="nodeTypeAlias" />
      <add Name="parentID" />
      <add Name="FileTextContent" />      
    </IndexAttributeFields>
    <IndexUserFields>
      <add Name="bodyText" />
      <add Name="umbracoNaviHide" />
      <add Name="productTitle" />
    </IndexUserFields>
    <IncludeNodeTypes/>
    <ExcludeNodeTypes>
      <add Name="image" />     
    </ExcludeNodeTypes>
  </IndexSet>