Personally i was mad at first when they added. They were making DoM easier then it already is by adding this. I loved being able to control mp. However after playing it a bit I found it really did not effect much. Then my opinion changed during a NM run where I could disengage during combat and while my party was fighting get my MP back. The concept of mp regeneration itself is fine, but if your party is engaged with a enemy you should not be able to regenerate mp whether your in combat or not.