Is there anything to Carl?

For most of the show Carl was the ladies man, player, gas lighter. He created drama by getting women angry at him and getting the occasional birthday cake shoved in his face. He was the guy who lead on the crazy twin, Paige (who he refused to take on a date in NY) and Lindsay (first time around). Then he became the sober guy and Lindsay's partner vs. the world.

But who is he? What are his actual character traits? Is he just a vapid, empty guy who latches onto people and events as an identity?