Just the 100% disease resistance and the dubious power of being a werewolf. You don't get a rested bonus from sleeping but other than that there's not really a downside to merely having the beast blood.
Should you actually use the power you'll find wolf form pretty fast with loads of stamina and a couple interesting abilities like an aoe fear and powerful knock down, you'll also find out that the form is actually pretty damn weak offensively and defensively.
And being in form has the annoyance of not being able to loot anything for the duration.