First of all, I have to say that the previous poster and I have a very different understanding of what 'close' means, as in 'close to the airport'. The Doubletree in Doha Old Town may be closer than, say, the Hilton downtown; 13 km compared to 19 km. But it still takes a fair while to get there, even when the traffic is thin.
Anyway, our recent stay was altogether enjoyable. The location is nice, the hotel is nice, the staff are nice, the breakfast is nice and if you keep your eyes open you should be able to get a very reasonable rate. We would happily stay there again.
HOWEVER -- and this is unfortunate because it has nothing directly to do with the hotel -- there is a major construction project just beginning (late December '18) in a lot adjacent to the hotel and there will be a lot of noise for the next weeks and months. Be sure to get a room on the side away from the work! You'll still hear it but it won't be as bad as if it were right outside your window. I reached two surmises about this situation. First, this construction project must already be behind schedule because the work continues well past midnight ( ! ) and resumes around 6 a.m. Second, it must have some influential backers that the builders can so blatantly ignore any 'anti-social hours' rules, especially in light of the objections one expects that the Doubletree and the other hotels in the area must have raised.