We were just there and I think it would be a great place for a honeymoon. Yes, there are many kids and families there (we had our kids) but there is a good-sized adult only pool. It's tucked away, and very private (and under-used). There's also a bar at that pool. There is an adult-only hot tub, but it is in a different location, and more crowded.
We had 6 people, three generations, in a 2 bedroom villa. It was amazing how great the soundproofing is -- we never heard anyone else if we had the balcony doors closed. So the rooms/villas are very private and chances are you won't hear screaming kids or anything like that.
The spa is AMAZING. Seriously incredible, you can easily spend many hours there before and after a spa treatment. They have special couples only massages too, in dedicated rooms. There were at least 3 weddings while we were there, so I assume like many hotels in Hawaii (DH and I were married on Maui), there is a wedding coordinator who you might want to talk to about honeymooning there.
It's a fabulous resort. Have fun!