Background:
I stayed here with my parents (three guests total) for four nights as part of a longer European holiday. We had several large suitcases.
The good:
An amazing location, a three-minute walk from Piccadilly Circus. This location offers immense convenience to do super touristy things in London. Check-in was very easy and convenient. The apartment's key surfaces were clean. Good quality bathroom amenities was appreciated as well. There were also plenty of pillows.
The notable:
Sofa-bed does not come with separate mattress. You will be sleeping on the cushions, which may not be the most comfortable.
The avoidable:
First, Iwona offered to prepare linen for the sofa bed. The linen was not prepared. Second, the circuit breaker had tripped and half the power sockets in the apartment was not working. Third, while the apartment's key surfaces were clean, there was some sloppiness in the cleaning -- old hand lotion was left in the bathroom mirror cabinet and an old towel was hanging on the bathroom door. Wi-Fi wasn't working the first day. It was sorted the next day after Iwona made a call to the internet service provider.
The bad:
This apartment is one floor above the ground floor entrance. You will have to carry any baggage up and down a very narrow staircase. 20" baggage is easily managed and 24" baggage is tricky but possible, but anything bigger is asking for serious trouble.