In particular, the former prevents the use of command word, spell trigger and spell completion items as well as the Combat Expertise, metamagic feats and creation feats (amusing). The latter, only specifies the skills that can be used and prevents any activity that requires patience or concentration.
1) [Pathfinder only] Is using the Combat Expertise feat an activity that requires concentration? Or is it left ad GM's fiat?
2) [Both systems] If Combat Expertise is locked out during a rage, are feats for whom it is a prerequisite (e.g.: Improved Disarm, Whirlwind Attack) locked out too?