Great little studio apartment in a fantastic location in Madrid. Right by a metro station and also walking distance to anything in Centro. The plaza at the door had a great mix of restaurants, supermarkets and cafes also.
We weren't entirely sure which building we'd be in because Six Rooms manages a few sets of rooms, but this was just a block's walk from the reception and in a great place. The space was clean and new with strong wifi. It was furnished sparsely, despite having a kitchen, there wasn't enough to really cook with, but the small fridge could hold some leftovers and a few drinks and there was a microwave. There was a shared washing machine and dryer on the floor which we used.
Check in was simple and we had great communication throughout the stay for anything we needed.