Thanks, Aethelwulf.
Oh and btw, I just realised there is one advantage Alliance locks have. Now it might not be much, but still.
On Horde, only priests have dispel magic. Shamans have offensive dispel which is very powerful for, well, offensive, but you cannot use it to remove warlock's dots and fears, should the feared target have it's PvP trinket and WotF (if he's undead) on cd.
There is a lot of Shamans and Paladins on both sides (I think they are in the more popular half of the classes) and when playing lock on horde, all the priests and paladins can remove your dots and fears (aside from curses, which are removed by druids and mages ofc), while playing lock on ally means that if there is no (usually undead) priest near you enemies at the moment your dots and fear's won't be dispelled.
I know this bonus in the lack of dispellers on the horde side does not mean alliance locks are in better position. I just felt I wanted to write it down and hear what more experienced players think of it.