[getfunky]

yes, the reason to raise is generally to limit the field, and that seems unlikely here. limping in from late position is a nice way to play big pairs for a several reasons:
1 you can get away from door pairs, live aces, and suited connectors without a second thought
2 you disguise your hand, especially when you pair your door
3 you mix up your play so that when you limp with a flush draw with 2 babes, you'll get more respect.
4 when you do fold 4th it will look like you played a speculative hand cheaply and failed to improve it on 4th .. this helps to prevent a tight image of laying down big pairs

the disadvantage is mostly related to disguising your hand, in that it will be more difficult to limit the field vs loose players who find reasons to call .. also, taking charge of the hand can help you get information based on the players reaction to the strength you showed from the getgo.