"Great location and staff and good food. Perfect!"
Me and my wife stayed at Koa Kea for 6 nights and 7 days at the beginning of Mar'17. The hotel is located in Poipu area, and is right next to the Poipu beach. It's very close to a shopping center nearby, and has multiple options for variety of restaurants and shopping (kinda touristy, but still nice). As I mentioned, it's right next to the Poipu beach, but away from where the general public access is. So, it's almost as if the hotel has its own private section of the beach. Hotel also has an activities hut where we could get surfing lessons, rent snorkel and general beach gear. Jacuzzi was great, we liked the bar and restaurant (a little overpriced, but everything in Kauai is generally overpriced). Waimea, Lihue, Kappa, and Hanalei are all accessible from the hotel (30-60 minutes via car).
I'd like to specifically mention that the hotel staff was really great, and always helpful. The hotel is right next to Marriott and Sheraton, and during our morning walks, we did see families with kids at those other resorts. But, during our stay, we mostly saw couples (young and seniors) at Koa Kea. Hotel room interior and decor was contemporary, but we felt that room was a bit small (that's the only "complaint" I had, according to my wife). Apart from that, a great resort, and a nice vacation!