I kept werewolfism for one reason: the disease immunity. I don't actually use Beast Form because it's vastly inferior to my un-transformed self in raw damage. I wish Beast Form added to your stats, instead of subtracting a bunch.
Tempted to keep it for this reason as well, though I don't like having to give up the 'rested' bonus.
On an unrelated note, is there a bug that causes you to lose perks, or do you start at a higher level than I remember? I thought you got one perk per level, but I just counted, and I have:
4 perks available,
2 perks in smithing
9 in destruction
9 in conjuration
5 in enchanting
2 in speech
which should mean that I'm around level 32 or so.
I'm actually level 38, unless we start at 5 or something rather than 1.