Not that this will resolve the issue, but can I once again reiterate that asking other people's opinions on unlocks in Battlefield 2 is pointless. Everyone finds the game different, I don't like the DAO-12, yet most people thik it is awesome. I like the P90 and the Mp7, again people don't share my views. Everyone finds the game differently, so I say, choose whatever looks coolest. If you then find out that you don't like how these guns work, than what have you lost? Nothing! An unlock can give you a very slight advantage, but only if you know how to use it. IN that way it is no different from a core weapon. It's just different, not necesarilly better.
So for those who chose to skip my sefl-rightious babble, I say choose the gun(s) that look coolest. Then, if you don't like the functionality of the thing, you at least get something sweet to look at.