Great place for a short stay in Madrid.
The checking process is increadible convenient and the checkout is late enough (12 pm) to not make you rush in the morning.
It is extremely well located (though the are is somewhat noisy/crowded, so it might just not be for everyone).
The only con I can think of is that there's some details, like furniture being old or a lil bit beaten up and are in need of some repairs/changes, but honestly is not a big issue.