Please take this review into consideration before booking at the State Plaza Hotel.
I created a TripAdvisor account just to write this review of the State Plaza Hotel, where I stayed this week to my great regret. I cannot pretend that my experience would be representative of all stays at this hotel, but it was so bad in enough areas that I think it warrants consideration by anyone who is trying to decide whether to book a room at this place.
I will grant that the room was reasonably clean, the bed was reasonably comfortable, and the building is reasonably located. It was everything else, however, that diminished any redeeming value that these qualities might have lent to the hotel.
First, I stayed at this hotel at the tail end of record-breaking high temperatures in D.C. that were comparable to summer weather in the city. In spite of this fact, the hotel literally refused to turn on the air conditioning, arguing that the hotel was equipped only with single pipe air controls. Until the temperatures were high enough -- with 80-degree highs that week, I wonder how much hotter it has to get for the hotel to be satisfied -- the management would leave the heat on and not turn on the air. When I called the front desk to request that they turn on the air conditioning, they simply told me to open the window and turn on a floor fan that the hotel provided. 
I honestly do not understand how the hotel believes that it could in good conscience subject its guests to these kinds of conditions. It is difficult to describe how miserable it was to lie in bed, trying to will myself to fall asleep while sweating profusely in a muggy and overheated room. It is also difficult to describe how uncomfortable it was to open the window when the only view out of the room was into the neighboring embassy and its residents. Even more difficult to describe is how I awoke at the crack of dawn, completely startled by the deafening sound of the garbage truck picking up dumpsters in the alleyway outside. Before I realized the source of the commotion, I mistakenly thought someone was hacking his way into my mediocre sauna of a room. 
My stay would perhaps not have been as horrific if I had at least been able to take comfort in a nice shower in my room. Unfortunately, the shower drain was not just slow -- it was so clogged and backed up that literally within seconds of turning on the water, the tub would begin filling up. Every three or four minutes, I would have to turn off the water completely, stand in the shower with the water off, and wait about four minutes for the water to drain out so that I would not run the risk of spilling the water out of the tub into the rest of the bathroom. 
My most significant complaint, and the primary reason for my writing this review, was the poor quality of service at the hotel. Perhaps the staff is more capable when asked to give directions to the Newseum, but I found them totally incompetent at fielding basic requests. I would have to ask them at least three times to do something before it would actually be handled. For example, when I called about the air conditioning, the front desk suggested that I use a fan. I asked if they had a fan, but they told me they were unsure and would have to call me back because it was not clear if they had a functional fan to give guests. If they had notice that the weather would be hot, as it had been for days, and that the management refused to turn on the air conditioning, why would the staff not adequately prepare to hand out fans to guests immediately, especially since they suggested these as a remedy? Ultimately, it took several calls to guest services and a couple of conversations at the front desk before I was even able to obtain a fan for the room. 
By the middle of my first night, sleeping in the room became torturous. When I called the front desk to ask that the air conditioning be turned on, I was assured by the night manager that it would be turned on the next day. Of course, this promise turned out to be too good to be true -- the night manager was just saying that so people would stop calling him to complain. All the hotel did the next day was turn on the fan in the window unit, which circulated lukewarm air around the room. Even this episode raises the question of why, if this was a possibility, the hotel's management did not resort to this method (however unsatisfactory) sooner. It appears from my conversation with the night manager, who expressed disagreement with the overall management's decision to keep the air conditioning off, that the State Plaza Hotel's management prioritizes cost-cutting over the basic comforts and needs of its guests.
I had to stay two nights at the hotel, and although the first day and night made me lose most of my confidence in the staff's ability, I maintained some hope that maybe they could fix the shower drain in my room so I could at least have a decent shower after working and walking around all day in the heat. I informed the front desk shortly after 7 am that I would be gone for the day and that the tub drain was in dire need of repairs. Since I made this request only once, the task obviously was not completed, and on my second night I found myself once again taking a shower in standing water.
I understand from previous reviews that other guests have managed to enjoy their stays. I do think that is possible, despite my experience. But I would also say that although this review seems to cover only an extreme situation, the indifference demonstrated by the State Plaza Hotel's management, exacerbated by the incompetence of its staff, leads me to urge any potential guests to consider other options very seriously.