Zombie makes you slow and lose normal healing though.
Zombies don't bleed, whereas vampires still do. I don't see anything in the interaction examples to imply there's no normal healing. The examples raws given are for raised corpses, but I don't imagine them performing better in the healing department. Looks like they also have extravision (don't need eyes to see,) can't feel fear (no bogeymen,) and don't need working nerves for movement.
Meanwhile: I actually hate lycanthropy, because it makes me drop all my gear on the floor. Limb regrowth is minimal in usefulness as well because generally if I've lost a limb I'm about to die anyway. Especially if I don't have the strength/agility/endurance/NO_PAIN/etc that comes with vampirism. Necromancy also used to lock all of your skills at their current levels. Not sure if that's still the case.
You can just sleep through transformation days, since months are very long in adventurer mode. What about nerve damage or pulping? You can lose the ability to grasp and come out alive if your legs still work. Unfortunately for vampires, that means your adventuring days are over, regardless. It was attributes, not skills, and vampires also have the tag.
Also you can get vampirism really easily. As for the not dealing with the hunger system part, that will be a problem by the time I can get ahold of a necromancy book. One does not simply waltz into a necromancer tower with a starting character. One does however beat up an unarmed civilian who happens to have doubled physical attributes and drink their blood with a starting character.
You can easily become a vampire or werebeast from toppling statues in a temple, although you don't get to choose which. You can obtain a book of secrets from a previous adventurer or fort mode raiding.