Man, the hybrid trope has been done to death but there's a reason we keep coming back. The vampire-werewolf split always feels like it's about reconciling two different hungers. One's this cold, calculated thirst for control and immortality, the other's a raw, chaotic need for pack and territory. The best ones I've read, like in certain paranormal romance series where the hybrid is caught between covens and packs, show the character not balancing them, but constantly failing to. They'll use vamp speed to protect their werewolf family, then hate themselves for the 'unnatural' advantage.
Honestly, most of the time the 'balance' is just a plot device to make the protagonist overpowered. They get the cool powers without the classic weaknesses, which gets boring fast. I prefer when the dual nature is a genuine disability—moon cycles that drain their vampiric strength, or a bloodlust that triggers berserker rage instead of elegant predation. That internal war is way more interesting than a tidy equilibrium.