We had a very comfortable stay for three nights in January. The location is great being close to Old Street, Barbican and Farringdon tube (latter is on Thameslink and national rail, so very handy, with lifts in case you are lugging luggage as we were). The warning about three flights of stairs was fair. I was prepared for it, but it was tough with medium size/weight suitcases (quite narrow staircase). Not for the weak!
The apartment was ideal for our needs. It was warm ( not cosy but comfortable) and pretty quiet due to double glazing. The bathroom was clean and functional. The kitchen is well stocked and useful if you like to cook on your travels as I do.
There is a tv, but not connected to much other than news. But there is good internet connection. The deck was nice, even in winter.
The bed was comfy. The sofa bed was so so. Folds in the middle so for one person you roll to the join. But it was fine for 3 nights.
All up, a great place to stay. Host was very friendly and helpful.