The booth is of great quality and allows me to record vocals at any time of day in a very sound sensitive building. Definitely would recommend also getting the ventilation system, otherwise you will run out of breath quickly. Intuitive building instructions, great out of the box insulation, and with a bit of extra acoustic treatment, very clean vocals.
Had to remove a star in the total rating because the item is only delivered to your front door (strictly speaking to the curb ("Bordsteinkante"), not into your apartment. Even after asking to pay extra for a delivery into the building, this was not an available option. Be sure to have neighbors or friends that can help carry the heavy packages into your apartment!