Dahlem is a quiet and beautiful part of southern Berlin. The hotel is located just on top of a metro station and S-Bahn station is 200 m away. Everything works, although the hotel is a bit worn-out. Rooms are clean, quite spacious and the wireless internet works well. Breakfast is good with a chef making omelets to your taste. If you don't want to stay in central Berlin, this could be a good choice. There is a shopping mall just across the street and some nice restaurants close by.

Yes, the architecture & ambience look a bit impersonal...but this hotel is very, very comfy and at about 80 euro a night, a great value, in my opinion. The rooms are large, the beds & linens are very comfortable. The bathrooms sparkle. There's a huge and diverse buffet breakfast, free wifi and free coffee around the clock. The rooms seem absolutely soundproof, which surprised me - I had the best night's sleep at a hotel in years. The hotel mainly seems to be frequented by foreign business travelers (lots of Japanese) and indeed I was booked here on business myself. The hotel is right next to the U-Bahn and therefore you're not more than 15-20 minutes from central Berlin. But the best part was the service. I forgot my power adaptor, but no problem - I could borrow one from the front desk. I needed change for the metro -- no problem, I could change bills at the desk. Everyone was extremely friendly and greeted me by name every day (and this is a HUGE hotel). I'll be back.

Great service, cosy rooms with a comfy bed. Never slept so good in a long time. I love that they only had an shower in my room and no tub. The cleaning was just superb. I'm already planing my next stay here :)

While the hotel is centrally located, service and breakfast buffet are excellent, you won't get much sleep in a hot summer's night, as the rooms lack air conditioning. You don't notice at first, since the lobby and common areas are all air conditioned. When we opened the windows in the room, it barely made a difference, except for the noise level from the surrounding streets, which by itself kept us awake.
The lady at the reception desk tried hard, but with limited success, to find us another room with a bearable temperature, as we refused the first one assigned to us, which felt like a sauna. Room temperatures were approx. 88 - 90 degrees Fahrenheit. With the windows open, it "cooled down" to around 83 in the morning.
When we questioned how a hotel that belongs to Best Western and calls itself "Premier" can do without a/c in the guest rooms, the answer was that it was considered by management, but deemed to be too expensive!
Therefore, my recommendation is "No" for stays during summertime.