We had a great time at Claudia's. It's a compact little apartment, with just what you need for a break in Madrid and no more. Comfy beds, well equipped, great location, cafes and restaurants all within 5 or 10 minutes walk, right near things yet still pretty quiet for a city centre site (even on Friday and Saturday nights we weren't unduly bothered by street noise, just take ear plugs if you need them).
We were amazed how close everything is, 20 minutes walk will see you to pretty much all the main sites you'd want to see.
Claudia was an excellent hostess, friendly, answering questions promptly, greeting us on arrival, offering some great recommendations. We'd happily stay again!
Ross and Lill