Edit: we ought to have a rigorous definition of consciousness before discussing whether such marginal cases are or are not conscious (or to what degree they are conscious). Since many books, like Consciousness Explained, tried to give a clear definition & explanation and still aren't accepted by everyone, perhaps there's no point in arguing about whether sleepwalkers are "conscious" or not as it will come down to different definitions.

As far as facts are concerned, and avoiding the c-word: brain activity during sleepwalking can apparently be quite high, since it includes whole subsystems working and reacting to the environment (walking around, using objects, dressing, driving...) This may be more than during (some? most?) dreams. But I am certainly not an expert.

It's true that "consciousness" or awareness or what have you is much lower than during full wakefulness. In addition to not forming memories, sleepwalkers can't pass for an awake person or hold a conversation, AFAIK.