The look of Aulani is very much like Animal Kingdom Lodge. I'm not so convinced that Aulani is an accurate presentation of Old Hawaii (as other bloggers claim). The lobby structure reminds me of the City of Refuge in the Big Island, but everything inside is very much decorated in a Tiki Bar style, although an upscale version. The rooms are comparable to other resorts. Overall, it is a chance for Disney to offer a new location to DVC members. I think they will succeed, but thus far, I'm not impressed with the property despite the amount spent.
One of the reasons I like Ka'anapali is Black Rock, which houses an amazing local ecosystem. Stick your face underwater and say hi to the tropical fish and sea turtles. It also breaks the waves a bit, but not so much as to make the water feel like a swimming pool, as lagoons often do.
I'm interested to see if the Disney service changes things. Most of the best beach locations on the island are owned by independent, not chain, hotels, meaning that there's no exceptional service guarantee. That Disney brand name and service may be enough to justify the $400/night for wealthier families.