Location is perfect, it is within walking distance to all the major sights in Madrid. Lots of food, supermarket, and cafe nearby, you can get anything here. Lavapies metro is just around the corner (we didn’t need the metro to get around).
Check in is not flexible as you will have to meet the host at a pre-agreed time. The host is a really nice guy though, if you prefer running on an open schedule, check in can be a problem.
Cleanliness is acceptable but can be better, the trash from previous guest was not thrown.
The apartment is fully equipped with everything you need, you can cook. One thing to note that the bathroom size is tiny and cramp, I am petite size and I found it difficult to take a shower comfortably without hitting the walls.