ok, after hours of searching I have finally found what I needed in one of the posts here, however, I ended up using google to find it, not the telerik search function...
What is either really missing, or impossible to find is this line here:
"RadScriptManager inherits from ScriptManager and simply adds script combining features to it."
found here:
http://www.telerik.com/community/forums/thread/b311D-bdbggt.aspx
What is really needed is a quick one liner in the documentation, under its own heading since RadScriptManager is a component, least I think so...