I enjoyed our trip last October to Aulani (and am scheduled to go back this April), but I don't think I would ever pay rack rates or have an Aulani-only trip. IMO, it is a great use of DVC points though.
The resort is beautiful and the pools are nice, but the lack of an adult pool is a big negative for us. Additionally, the food quality/variety is lacking and I didn't think the service was anything out of the ordinary (We reserved an ama ama casabella for two days and our attendant forgot to put our lunch order in, delaying our lunch schedule by 2 hours, a one-off incident but still, not great for the price point). Cabana service was better but the food variety issue still stands. I also found the resort stores lacking in selection.
We loved the quiet Ko Olina location (we live in a city so don't want to stay in one on vacation) and didn't find the drive to most major attractions too much of an issue. The grounds are beautiful and the walkability to the boutiques and ABC store was great. On-site car rental was a big plus and we enjoyed having an on-site luau.
That said, I would not have a trip where we *only* stayed at Aulani. There is so much more to see and do on the island, that would feel like a waste to us. Aulani is a lovely and relaxing place that we enjoy using as our home base, but it doesn't offer enough for us to ever justify a resort only vacation there or a stay at full rack rate.