Werewolfs are cool, but unless you have dawnguard DLC, it is honestly sort of pointless except for RP purposes. Unlike being a vampire, there is only one real small negative effect (no more rested bonus), but it eventually gets to a point that you are killed faily easily by almost anything. WITH dawnguard. it becomes FAR more powerful with the per tree, and you can even take down some of the lesser dragons as a werewolf with decent ease. Once again though, it CAN eventually get to a point where it becomes almost too much of a glass cannon and takes basically no hits. IT is VERY fun when you are able to use it (on bandits, it can be hilariously fun for example) but your humanoids form eventually surpasses it in strength sadly.
As i said before though, unlike being a vampire, there are no big negative effects (just do not transform in front of anybody) and it is powerful early on, it just becomes almost redundant later on IMO. Of course, IMO, it is STILL much better than being a vampire, which has very few real advantages and some serious disadvantages.