We had a great time staying at the Wilderness - we stayed at Glacier Canyon Lodge, and the room was very nice, clean and roomy. I liked having 2 bedrooms and a kitchenette for our family. We also had a blast going to the waterparks. Its a place our family likes to visit at least one time a year as a little getaway for a weekend, and the kids always have so much fun especially in the wave pool.
Also I have visited the Sundara Spa before too, and I loved the experience there. I had the bathing ritual - which was very relaxing before my hot stone massage. I would suggest trying this if you have a couple of hours to get away.