I've stayed in Q-Bar a number of times for work and while the other reviewers comments about the music and the bar are true, I've never experienced any problems, and know that on weekends especially there is going to be music and noise in the bar.
That kind of reputation can be intimidating for a woman staying solo but in fact the staff have always been helpful and friendly, and the separate upstairs restaurant area means you can get away from the main bar if you want to.
The food is good and quick and amazingly the only thing that has disturbed my sleep there is the dogs next door.
There is a shortage of good mid-range hotels in Dar and Q-Bar is reasonably priced and in a good location for the peninsular and down-town. The rooms have always been clean and the breakfast is very good.More