I broke my contract with PAM. I was on the path to make about 28k with PAM, and I signed on with Werner (Similar Companies, but I was making .26 CPM at PAM, and .32 CPM at Werner) and made about 40k instead. I payed about 4.5k out of pocket to Driver Solutions for breaking my contract and ended up making more money out of the deal. Breaking the contract won't affect your DAC, won't stop you from getting a better job. I don't think that Driver Solutions even bothers to pursue most of the money owed (I know two guys that just flat never payed them, and they're both still driving 2+ years later).
After I got a year's experience at Werner/Pam I moved on to Con-Way truckload, when I get 3-5 years here I plan to go to Wal-mart, or Fuel Hauling.