Vampies take 40% more damage from Fire off the bat and reduced health regen.
In PvP players with the Slayer line of skills do 9% more damage to them and things like Evil hunter proc more often on them.
They have a long skillline that you have to level to get their benefits which are:
They can get 10% Magicka regen and 10% Stamina regen.
They have access to powerful abilities like batswarm and mistform
They get undeath which reduces the amount of damage done to you when you're closer to death.
They move faster in stealth.

Werewolves get 15% stamina regen in human form and werewolf form and have zero negatives for remaining in Human form.
You get this bonus the moment you become a werewolf.
In werewolf form you get access to werewolf abilities but they're still pretty bad in PvP and it's generally a waste of Ult.