We stayed at this apartment for three nights out of five booked. Check-in was very easy and the location was great for exploring Lisbon. The apartment is just as described and comfortable and modern. There were some issues with drainage in the bathroom sink. We decided to cancel our stay as on the third night the noise level from partying on the street, and bars close by was extreme up until 6am. We didn't get any sleep and we were concerned that this would continue for the rest of the stay (the first two nights were Sunday and Monday, so we thought it must have been quieter because clubs were closed). We later learned that the noise level may have been particularly bad because it was a national holiday that day. Either way, we cancelled our reservation at a point where no refund would be given anyway (our choice and we knew this), but the communication with GuestReady following this was quite abrupt and unaccommodating. I understand they have a business to run, and some things may have been lost in translation.
Main point: be prepared for noisy nights, and maybe only stay if you're a heavy sleeper or plan on heading out most nights anyway!