I only know 7 and 9.
Limit Breaks (FF7):
PROS: generally useful, could be saved and used at will
CONS: can't attack until Limit is used, Limit Break lost if dead
Trance (FF9):
PROS: sometimes useful (could give extra advantage)
CONS: used automatically, no chance to take back previously given command (thus wasting a turn of it), often comes at end of battle right before someone else finishes off last foe (rendering it useless), can be confusing to newbs (more so than Limits), Trance guage emptied ifdeadhit with certain status ailments.