I was wondering just how useful the Alteration perk "Mage Armor" is. If Skyrim is the same as oblivion, the max armor rating should be 85? My stoneflesh spell, even without this perk gives me 60 rating, so wouldn't it be a waste to get this? Or is the armor rating different in skyrim?
Also, will picking "Magic Resistance" make the "Atronach" perk weaker?
Thanks in advance.

And it'd be nice to have an answer to the second one also! If anyone knows, please tell! It would be a shame if it actually does make Atronatch weaker. Hopefully it dosen't.