Stayed with our family of four (kids age 2 and 4) for 3 nights and the flat was perfect. It is very large and in a great location. We parked a van in the garage (with a lot of sweating) but otherwise had a great time. The location is truly amazing with grocery 1 block down and a popular overlook 1 block up. Washer in the kitchen was great for us to clean clothes and the place is very large. 900 sq ft by US standards.
Catarina was very helpful and everything was easy breezy.
Parking: it is a tight garage and is 4 levels down so you have to make a tight turn 4 times. By tight I mean you have 1-2 inches on each side of the car. As we had a minivan this requires us to have one person outside the car to guide and many adjustments. But as I said it is possible for an American in a rental so anyone can do it! We had no scratches.
Try to park on the street to save yourself the stress :)