I've stayed in both...

The Royal property just feels more like a resort to me than the Moana. The grounds are nice and there are more trees. It's set away from the main drag and seems larger and more relaxed.

The Moana is right on the main street. A beautiful entrance but the beachside is nothing special.

I would choose the Royal Hawaiaan. Rooms are comparable but maybe a little bigger at the RH. The pink is really sort of fun. Pink robes, pink stiped awnings. It's definately like you are stepping back in time.