We were 4 girls staying in Lennards apartment for 4 nights and it was perfect for us. It looked like described as in the pictures and it is really central. Just across the street you find a metro station which is in the city centre in minutes. You will find supermarkets and restaurants just outside the door and the transport from the airport was really easy. The communication with Lennard was really good as well.
My friends and I would totally recommend to stay in this apartment in Stockholm! It even would fit more than 4 people easily.