I would drop the 2x Electrickery and 4x Vampiric Fury in favour of 2x Dreadbore and 4x Bloodline Keeper  ^Flip . I'd also suggest a minimum of 22 land, 20 while seeming sufficient is often very inconsistent and can force more mulligans than its worth. You might want to look at switching out the 3x Falkenrath Exterminator for 3x Vampire Interloper , this might seem a bit of an odd choice but the added avoidance of the interloper with flying means its far more likely to do consistent damage and get counters from Rakish Heir than the Exterminator. You may also want to consider adding 4x Deviant Glee the added bonus of +2/+1 speaks for itself but the ability to give some big creatures trample that could otherwise be chump blocked is amazing.

Ironically, I took out Deviant Glee but I'll happily put them in!

Just curious though, why take out Vampiric Fury when it can temporarily buff all my vamps? It has definitely saved my life more than once.

Well to me it seems a lot less consistent than something like Deviant Glee especially considering a lot of creatures start small, if you can make them less small to begin with the chances of them getting a lot of counters increases. I'd say its a decent sideboard card, if you come up against other aggro decks.

Fair point. I mostly play against fast aggro or milling, which is probably why I use Vampiric Fury a lot more than Deviant Glee , especially in early game!