Overall, the Umstead is a gem in the Raleigh area. It is truly a 5-star experience, but it is not without some faults. My review comes from the perspective of a Marriott Ambassador Elite member and someone who has stayed >3,000 nights at hotels around the globe.
The hotel, and the grounds in which it sits, are spectacular. The setting is serene and definitely encourages you to relax and take in the natural beauty of the area. The hotel is spacious and very clean. Inside the room, you'll find all the modern goodies like a connected TV, smart lighting and very comfortable bedding. The room smelled neutral, which isn't always a given. Outside the room, the balcony was great in the morning and evening, where you can enjoy a relaxing time overlooking the lake and fountain. Downstairs in the common areas, the furnishings were modern, the bathrooms clean and the common areas inviting.
Where I think the hotel fell a bit short of expectations - surprising so - was with the highly rated restaurant. Since the restaurant was closed on Monday, we ate from the limited bar/dinner menu. Although the portions were very small, which we expected, the meal was very salty. We ate in the restaurant for breakfast the next day and after 2 attempts to scramble some eggs dry, we gave up. The eggs were swimming in oil and inedible. On top of that, our breakfast was cold, the waiter spilled coffee all over the table and the service was inattentive and slow.