Moderator: Global Moderators
Well I can mostly speak from a mage's perspective since i spent most of my time on wow playing one. I would say from the outset that both classes are great fun to play and easy to level: which one will suit you more depends on your playstyle or preferences. I can safely say that mages are better at endgame instances since they have better mana efficiency from their spells as well as reduced threat (from talents which you will pick anyway whichever tree you spec into). Mage aoe is also the best in the game. The mage class gets several useful abilities, such as conjuring your own water and food (some consider this a curse ) and portals to move quickly around. In pvp, I would say that we can suffer at the hands of certain classes, while beat others to crap. The ability to sheep someone (usually a healer) will help a lot in group fights.
. One on one they are one of the most feared classes in the game. Other useful abilities include summoning of people, healthstones and soulstones (quite important in instances to reduce downtime after a wipe). One of the downsides of locks are soulshards since they use them for most stones, pets, summons etc, and thus have to keep a fair supply all the time. Perhaps someone more knowledgeable about locks can add something here 
