Pros: Location was really great - lots of restaurants, 5 min walk to victoria station, 15 min walk to buckingham palace/westminster abbey. Felt safe with the 3 locks you have to get through to get to your room. Communication was good.
Cons: As others mentioned, the mattress really needs to be replaced. So unbelievably uncomfortable (feel every spring). The sheets are all stained and ripping. The duvet is lumpy and pillows are not acceptable at all. It wouldn't be that much money to update these to satisfy guests. I have honestly never had worse sleeps in my life. Towels are so bare and rough. Bathroom was dirty - garbage filled to the brim, sink plugged with so much hair it was draining slow, and hair all over the bathtub. Yuck.
Overall opinion: Having a great location is key but it's really hard to give a good review when the place is so neglected.