We had a very pleasant stay at Montse's. We had a warm welcome and the host immediately sat down with us to show us the map of Barcelona and gave us some tips for nice things to do. Everything was very neat and tidy and there were lots of facilities present (hair dryer, towels etc.). We even had a small balcony where we would drink our coffee in the morning sun. The bedroom is quite small, so we would recommend it to individuals or couples who plan to use the bedroom only for sleeping, otherwise it might be tight. The house is on a crowded road and because we read some reviews beforehand about the traffic noise, we brought some ear plugs just in case. I guess it really depends on what others prefer, we eventually didn't use the ear plugs at all.
The house is also located near Sagrada Familia and a couple of subway stations, so it's really easy to get to the city or other sights.
In short, we would recommend staying at Montse's home if you don't mind sharing the bathroom with other guests. It's perfect for individuals or couples who want to discover the city of Barcelona for a couple of days.