Disappointing. I booked this place to have a productive workplace while visiting friends in Germany, but the WiFi was completely broken for the entire stay and I had to find alternative workplaces for the week. Jeffrey responded once to this concern (suggesting to ask neighbors or go to a nearby cafe), but said the Internet provider is painful to deal with and then ignored my messages for the remaining duration of the stay. These things can happen, but Jeffrey didn't seem interested in solving the situation or making up for it.
Don't book this apartment if you rely on Internet or need a communication channel to your host.
Aside from this, the apartment was cozy and comfortable, as other reviewers have pointed out.