I just went to the barber shop to clean myself up before asking Serana to give me (a Dawnguard with a Dwarven Crossbow) the gift

Personally I find the Vampire artifacts better than the dwarven crossbows, I've done both sides.
Becoming a VL on the Dawnguard side pretty much gets you kicked out of the Dawnguard, the armored trolls are weaker than the gargoyles even when both are scaled to master difficulty....and the Gargoyles are free!
Becoming a VL on the Vampire side with the artifacts is a literal monster, also I get attacked by so many dawnguard in the wilds I've been picking up crossbows of flames/frost and draining and a ton of bolts also we can turn our spouse into a Vampire which can be any NPC in the game excluding werewolves...sry Aela, i turned Lydia. =P
Vampires 1
Dawnguard 0