We originally booked apartment 11d, but were moved to 11a when we arrived. I don't think there is any real difference between the two. 11a is lovely.

The location is great - a 5-minute walk to Kochstrasse U-Bahn, and in the other direction Hallesches Tor U-Bahnhof is about 10 minutes away. The location is a very short U-Bahn ride away from Unter den Linden.

This building is extremely quiet. We were there for 11 nights and at no point were we bothered by any noises. There is construction nearby, but that didn't seem to start up until after 08:00 when we were already awake.

The apartment is very comfortable and unbelievably clean. It appears to be newly remodeled, and would be comfortable for a stay of any length. The apartment is up several flights of stairs, but that was no difficulty.

The temperature was always comfortable, and we were able to control it. Water temp and pressure in the showers (no tub) was great.

Internet was fine. We frequently had four people connected simultaneously and it was always fast enough. We also got good cell reception in the building on our US phones. The TV worked great and had plenty of channels. There is a DVD player and some videos.

There is a dishwasher and plenty of glasses and plates and flatware. There is a stove and oven, a toaster, a kettle, and a coffee maker. All were in perfect working order.

There is a Kaiser's grocery store about 5 minutes away from the apartment. You will need to stock toilet paper and might be a good idea to get some extra paper towels to you can clean up after yourself in the kitchen a bit easier. Pick up some soap too.

Bear in mind, you will have to wash your own towels and bedsheets. But the washer / dryer combination appears to be new and it works well. There were plenty of towels. The beds have feather comforters, not sheets and blankets (it's Europe) so be prepared for that if you're used to American beds. But the beds were very comfortable.

The process to gain entry to the apartment was well communicated and easy. We had keys for everyone in our group (four adults). There is a storage room to drop your bags that is secure, so even if you show up before the apartment is cleaned and ready for you, you will not be stuck with your bags for the day. The front gate to the street is heavy and requires a key to enter the courtyard.

There are a few bars and restaurants nearby. Checkpoint Charlie is right at the U-Bahnhof, so there are a lot of tourists around, which means Starbucks is close by (not meant to be a plus). Restaurant choices are surprisingly good - there is a Michelin-starred restaurant just next to the U-Bahnhof.

Overall, I highly recommend this apartment and this host. You will be comfortable, safe, and close to nearly everything.