It's very useful at lower levels, but after you start enchanting and smithing your own weapons, it becomes increasingly more obsolete. You are only able to transform once a day, so no random transformations. It doesn't require you to feed or anything. The only difference you'll notice when you become one is NPC's will have werewolf associated dialogue, such as "you smell like a wet dog" and "you have a wolfish grin" (not direct quotes, but that is a summary of what they way). Also, you won't be able to have any rested bonuses, which is a turn off.