Board Thread:Online Discussion/@comment-99.194.28.74-20140619035550/@comment-24325144-20140717074133

Only if the Dragonborn joins them. The dlc begins with the Voliihar clan decimating the Vigilants of Stendarr. While the Dawnguard goes around begging for recruits, even in the quest destroying the Dawnguard killing all the "main" players was extremely easy. While killing Harkon is completely different.

The only thing I regret missing out on with the Dawnguard are the huskies, I'd like to make them my pets for my kids. But that's all that's really to miss out on, even joining the Volkihar clan allows the Dragonborn to get the Dawnguard spells, but joining Dawnguard makes the Volkihar spells inaccessible without console commands.