Opportunity: PvE > PvP > Leveling
 
	Master of Deception: PvP > Leveling > PvE
 
	 
 
	The extra damage from Opportunity in raids and dungeons (assuming you're using daggers) is amazing. The extra stealth levels from Master of Deception for PvP and some leveling is great.
 
	 
 
	Just my opinion though, half the fun of WoW is playing the style that you like.