I'll solve the werewolf/vampire issue with just being one of them with one character.
It is stupid you can't be both but... *shrug* guess i'm just used to idiotic desing in games.
The way getting werewolf powers back does sound extra stupid though... just once?
Joined the vampires, feels good so far. Vampire lord feels pretty powerful, 3 trolls i would have hard time fighting them in human form were a piece of cake. Gotta say it would have been intriguing to stay as a member of Dawnguard but... well, with another character then.
However, Bethesda's been lazy or stupid again and you cannot use first person with Vampire Lord. Horses, werewolves, now Vampire Lords, why? Just because they can't be bothered to add alternate arms to first person view?
Also, crossbows are really, really good. 21 damage (15 Archery, no perks), whoah (orcish bow does, what, 8-9 damage). They do reload quite slowly and during reloading your movement does slow to crawl so i guess they're balanced. Excellent weapons for non-archers should they need a ranged weapon, good weapon for archers too though i think versatility of bows is better for them.
Did the DLC add any new spells for mages though?