Mersins place is as per the photos, its nice and clean.
It located within easy reach of attractions. The single bed as mentioned is slightly narrow, but you could sleep on it, if you are small frame. The place is quite at night, but you do get woken up by the first call of players at about 4 in the morning, I suppose this would be no different in any part of Istanbul.
Their is no lift in the building, the flat is on the second floor, and slightly winding staircase. This may be a bit difficult if you have a large suitcase to carry up. For those travelers who are vegetarians and vegans there are places on the street catering for them and in the near vicinity.
Mersin has been very helpful, resolving and minor issues you have in a timely manner.