Werewolves aren't really that strong (I heard Dawnguard changes this). You HAVE to use the fear totem inorder for enemies to constantly be fleeing you and thus not attacking. This being said, not all enemies are affected by fear (giants), and I have yet to find a way to deal with such enemies as a werewolf.
Giants are easy. Sprint past them and hit your attack button while sprinting when you are next to them. If it hits, the attack will knock them over, and you can hack and slash away until they get up, and even then, a normal power attack will knock them over too.
Btw, did the Dawnguard werewolf perk-tree make them a bit more useful in the higher levels?
Yes. You can get more bonuses to health and stamina, improved health regen from feeding, several damage increases, improvements to all 3 totems, and even gain the ability to feed on most creatures instead of just the sentient races.