TempelCasa is perfectly located in Kreuzberg, one block from the Landwehrkanal and a couple of blocks away from some of the main shopping streets. The street it is on is very quiet, with bus and U-Bahn stops close by. The apartment itself is immaculately clean and well-appointed. The mattress on the bed is great- I have seldom slept so soundly. The wifi worked perfectly and the tv reception was excellent.
Alexander was very responsive to any questions or problems we had. For example, the stovetop didn't work and he called an electrician right away. There are a couple of things to be aware of about TempelCasa: 1.) Hand soap is provided in the bathroom, but you should bring your own shampoo and bath soap, and 2.) Because the apartment is semi-subterranean, you won't get a lot of daylight coming into the apartment. The windows have translucent blinds on them, though, and privacy is no problem. Tipping the windows open provides plenty of fresh air.
In summary, we really enjoyed staying in this apartment and would do so again.