We stayed 4 nights in a 1 bedroom apartment that overlooked the courtyard- it was very quiet at night. The apartment had a washing machine and dryer which is very handy when you are travelling for long stretches. Kitchen facilities were good and as mentioned previously there is a bakery on the corner. There is also a Lidl supermarket within walking distance(not open on Sunday) and a Kaiser supermarket at the hauptbahnhof.
Walking from the hauptbahnhof took about 10 minutes and the Naturkundemuseum Underground station was less than 10 minutes away. We walked to several of the tourist attractions but there were many places that we used the trains for and it was most convenient having either station nearby.
Staff were extremely helpful and very polite. Would love to stay here again on my next visit to Berlin.