I stayed in the Master Suite at MX Hotels Maison Salamanca for three weeks. The room itself and the location were amazing. I was working remotely and there is a desk which was nice, and the internet in the room was good 95% of the time. The other 5% there was always plenty of space in the little cafe in the hotel to work.
My one complaint is the noise, which others did mention. I brought ear plugs and was prepared for music and city noise, but there is construction happening in the building next door which is right behind the wall where the headboard for the bed is. They commonly were working from 7pm-11pm on any day of the week. I reached out about this and was basically told too bad. I would say there were 7 days out of 21 where there was very loud, wall shaking construction past 8pm.
Other than that... it was great! Just keep in mind the above and if you're a night owl tourist, know the location is amazing and the room is beautiful.