The bonuses vampirism provides are easily replaced by leveling your skills. After that - you only get the drawbacks.
this. just like lycanthropy, the bonuses soon become pointless because the game is already so damn easy. bethesda really needs to think about what the damn purpose of these things are- to play as something different. to feast on peoples blood, control minds and make thralls, to eat people and howl at the moon. to an extent they do this, but everything but the animations you can already do to great effect without the drawbacks. there needs to be something unique about vampirism and lycanthropy that doesnt become irrelevant once you level high enough.
being a werewolf has something going for it with the "unstoppable monster as long as you keep killing" aspect, but again the game is already so easy you find yourself clearing a dungeon with minutes left and the "unstoppable" part dies down as you level because for whatever insane reason werewolf form scales to a hidden skillset you are never told about.
vampirsm has something similar, if it wasnt completely backwards. feeding makes you weaker but socially acceptable... why is the primary vampiric trait presented as a detriment? most of the game is spent locked in a dungeon, so oddly enough you end up only draining someone's blood when you want to sell them stuff, which just makes me cringe at how nonsensical that sounds. they could easily make the health drain your primary power, maybe give it a blood svcking animation, maybe stunt your regeneration all the time so that feeding is your primary means of healing... something. its supposed to be a different way of playing, not a few novelty abilities coupled with annoying drawbacks.