The location is really great, really a few feet away from Gran Via and Chueca, the noise isn't too bad because the windows aren't in the principal street and it's a bit calmer. (we didn't hear people partying or screaming, only cars and garbage collectors)
The flat is quite big and well equipped (except for basic cooking ingredient like salt, oil, but there is a super market in the same street)
For us the bed wasn't comfortable enough (basic ikea matress) it depends on people and it's good enough for a few nights.
We wouldn't hesitate to come back again!