Hello, i am not a vampire and i dont want to become one as i dont want to mess up the look of my character and dont like vampires in general. But the magicka/stamina regeneration and damage-mitigation passives alone are so good, that i feel if you want to get the most out of your character, you have to become a vampire.
I know that it is easy to reach caps but from a min/max competetive pve-perspecive, even 0,5% regeneration or 1 additional cast per minute matter (numbers made up). ESO is not a vampire-game, so it would be nice to have a choice. At the moment vampire skills/passives are an improvement for every class and every build and not having them is a disadvantage.