This past summer we stayed at this Chicago hotel for a week and it was an good but improvable choice. The Doubletree is a mid-range brand which is part of the Hilton chain and is generally designed for business travelers (I'd put it in the 3-to-4-star range). For the price and service, this particular hotel is closer to four stars but a lot of the services are extras. The location is great, just two blocks from the Magnificent Mile and a ten minutes' walk from Navy Pier. On this front, no complaints.
The facilities are correct and appropriate to the hotel's category. The rooms are well-equipped and properly sized. The outdoor pool is in good shape and has nice views of the surrounding skyscrapers. The lobby is spacious and nicely decorated, with a lively but somewhat expensive bar.