I have both of those, the 8-page one for RMC and the 252-page one for "Rolemaster" (I believe it is for RM2/C). Other than that, I don't know what to tell you about it; it is Dark Sun done with RM rules, just not RMSS/FRP. I would say though, that if you are going to run Dark Sun, take a play out of the RMU playbook and set the characters at least at Legendary power level, probably Epic.
Gawds! What I would give for someone to run that for me. Dark Sun is my all-time favorite fantasy setting (Shadow World is a close second, so Stay Calm Everyone, and Game On) and I would drop playing any other game if that one came along.