I made also another reply in Developers discussion section but I will make it here, just to see what people think about it and finally Devs to see what players want from them.

Well first thing which will balance WW with Vampire is making the transformation completely not ultimate based.

Use your creativity and imagination and make something like:

- while you are in human form if you do x amount of physical damage or if you kill some amount of enemy players mobs etc.(that could be something like sacrifice for Hircine) once per real life day you get chance of transformation to WW for let's say for 60 min or so(for the first transformation!!), and the next time you eat corpses you extend your duration in WW form but for 25%, 50% and 75% of it's first duration in one day, so this means you can basically feed 3 times after first feeding in day!(calculate the whole possible duration in WW form)! This does not have to be like that it's just example,

-next thing is please remove the poison weakness, and add passsive which grants a 100% resistance to all diseases.Fighters guild skills and pasives are enough for countering WWs, also you could change some passives in fighters guild if you see this last thing too much OP which I think is not.Like in Skyrim Dawn Guard had Silver bolts etc. I know we have them but with this example it could get slighty buff even if it's now already deadly...

-logically passives should drastically increase damage, stamina and health( make like 3 passive skills x amount increase per each), feeding which exstends duration of the WW form should also restore x amount of health and finally make a ultimate for WW ,something like call of wolf pack, which would be something like 3 wolfs summoned and aiding youfor x amount of time.

-i forgot to mention increasing armor and spell resistance by x amount ! thats important also!
make more stamina and health regeneration as it should be, make him run some 30% faster than now

This is real example how to make it more balanced and realistic compared to Vamps(make them the Vampire Lord transformation option just to stop them whining).Even that would be too much as they have the pale skin color, werewolfs don't have any body marks which is nice ?.
If there is someone who thinks this is too much, just look the fighters guild skill line there is plenty things which could get a buff to counter WWs.