I've stayed in this hotel for two nights (January 2015), in their North Tower. Due to traffic and constructions/building going on, it is important to ask for a silent room. The check-in process was very pleasant and when asked for such 'silent' room, I got upgraded and got a room on 36th floor. The room was very nicely furnished - bright (huge, full wall size windows), modern, clean and practical, to include large bathroom with a separate bath and shower. Whilst I paid for the breakfast, I didn't use it so cannot comment on its quality. When I mentioned it at the check-out, it was removed from the bill without questioning. One can have a small breakfast in their café on-site instead too.
There are several restaurants too chose from; we ate in the Brazilian place (I wouldn't rush back there - it was OK'ish) and in their New York steak place (the quality of food was very good, the service didn't have a great start but improved in the end).
The gym is small but functional. The swimming pool was good (didn't swim but checked the water - which was heated... useful even in Qatar in January!). All in all I would stay there again.