My wife and I stayed at this nice apartment for almost a week soon after covid travel restrictions from the US were lifted by Spain, and took full advantage of city's reasonable prices and low tourist numbers.
The place is clean, functional, if a little tight (as specified), and located in the Gothic quarter of the city, putting many historical landmarks, stores, restaurants, shops, Gaudi architectural masterpieces, and beaches in the walking distance, while also being super quiet.
Carlos responded to questions and inquiries very quickly. There was a provider-caused internet outage lasting couple of days, but Carlos worked with the provider diligently and proactively, and got them to fix the issue. Once fixed, the internet was super fast and rock-solid. (Fellow US-based world travelers should get Google Fi cell service to not worry about internet issues abroad.)
When our airline delayed our flight out of Barcelona by almost four hours, we asked Carlos whether we could check out an hour later than specified by the contract, and he graciously let us check out later.
We would definitely stay there again and happily recommend it to anyone.