We had a great stay at Marta's and would absolutely recommend it to anyone. Amazing location within easy walking distance of everything we wanted to see (although our taxi was not able to drive right up to the door due to some pedestrian-only areas, so we did need to walk uphill a bit with some heavy luggage, so would take that into account).
Self-check in was simple and the place itself was pretty incredible. Very unique experience to be surrounded by so much history! We were very comfortable, great shower, good wifi connection. Marta kindly checked in on us and although we had no issues, I have no doubt she would have been responsive if we had any questions/needed assistance.