Possibly one of the best threads on SRK, this explains the EX moves and compares them to the normal moves, they are not necessarily as good as you might think!
Example: Boxer EX headbutt does less damage than HP headbutt
Check it out!
http://forums.shoryuken.com/showthread.php?t=179574
Remove Mask
Damage: N/A
EX Properties:
-Removes Mask instead of Claw
Uses and Notes:
-Expends two EX bars instead of one
-Vega does 10% extra damage without his mask
-LOL