kdyal,
I am also a RM2 GM/player, and still am. I bought the RMC books to support ICE and to see what they did with the new version. I will always change "the standard rules of Rolemaster" to suit my game and my vision because that has been a great strength of the system since it was released IMO. Given that, a few quick thoughts:
Character Law: An OK revision, the updates here were relatively minor. It tried to make it easier to understand how to make a character, but I know someone unfamiliar with RM who tried and failed without help. It's difficult unless you know what to do despite the changes.
Spell Law: Good update, clarified spell uses and descriptions. I don't agree with about 10% of it, but change as I see fit.
Arms Law: Another good update. Again, I differ with about 10% of the "rules" that were clarified, but it is very helpful.
Creatures and Treasures: Excellent update. What I like most is that it clarifies the abilities of creatures and how they are used. Highly recommended.
Good Luck, Grafton