Of course, I had 'problems' with it at first. The only real problems I had were the Vampire Attacks, and the fact they can start rather early in the game, and they won't stop until Dawnguard is complete. The Vampires can hold their own with the guards for a bit, but they eventually fall, but kill several villagers in the process. In one such attack, Adrianne Avenicci, Ulfberth War-Bear, and Belethor were all killed within one attack - and they're the only people I ever sell my loot to! So they hit hard, fast, and early, and it ain't no fun.
So basically, before starting my new character, I am planning on REMOVING the DLC from my Xbox memory, and then re-install it at a later date.
Would I have to pay for this? Should I not delete it?