Thomas' place is well located with regard to Tegel airport. Getting to and from there is easy. Connections toward any other direction is smooth and there's a lot of possible means of transportation available. There are also a couple of really nice cafes down on the street, and a few nice food places just around the corner, so the location is really good.
The flat itself is spacious and comfortable. The kitchen is really well equipped, especially for Berlin. Can't remember having a dishwasher before! Also the bathroom is nice, compared to many other places around Berlin.
Overall we were really happy with our stay, and I will probably first look for this place, when coming back the next time.