I've stayed at the Doubletree Resort a few times while in town for business. Unfortunately, I don't get to take advantage of many of the leisure facilities, but the pool seems nice and the grounds are attractively landscaped. Its location is excellent - either a long walk or very short drive from old town Scottsdale. Other resorts with golf courses are nearby.
The rooms are large and have balconies or patios. My biggest complaint with the rooms is the bathrooms. They're kind of small and seem of low quality. The fixtures, tub, etc. feel as if they're more motel quality than luxury resort.
Service is friendly, and hey, they hand you a chocolate chip cookie when you check in - so what's not to love about that.
Overall, it's a great place to stay and earn Hilton points when I'm in the area for business, although there are nicer options if you're there for business and looking for the luxury resort experience.