I was very pleased with the A&O City Hotel. The facility is both a Hotel and Hostel.
Although I booked a single hotel room (avg price $45/night via Expedia), I received a relatively spacious double room on the 2nd floor. There was a desk, cabinent and a small television on the wall. The room and bathroom was spartan but clean. The heating worked well and you can open the windows, if you desire (electronic exterior blinds). Although the hotel was located on a busy road, it was relatively quiet. The hotel uses a Cardkey system, so I felt the hotel was secure.
The hotel is about 5-10 minute walk from the Hammer Kirsch Ubahn stop (U3 line). This Ubahn stop is about 10 minutes from the main train station.
Getting from the airport to the hotel was relatively easy. I took Bus 110 (every 10 minutes). The cost was 2.50 Euro - pay the driver, the ticket is good for the entire trip. Take the bus to the last stop (Ohlsdorf) and transfer to the Sbahn (S1 or S11). After 8 stops (Berliner Tor), you transfer to the Ubahn line (U3). Two stops later you are at Hammer Kirsch. Total travel time is about 35 - 45 minutes.
There is a faster/direct/expensive route. You can take a bus directly (every 20 minutes) to the Main train station and then take to U3. Three stops and you are at Hammer Kirsch. I estimate the total travel time to be about 25 - 35 minutes, and I believe you pay seperately for both the bus and the Ubahn.
At Hammer Kirsch, there is only one exit (there is an upper and lower exit). For either exit, you would turn left. The upper exit leaves you at the top of the hill. You take another left and walk downhill the street to Hammer Landstr. You take another left and walk a few minutes to hotel.
The lower exit is a pedestrian subway that will take you directly to Hammer Landstr. After you walk up the stairs, you turn around and walk to hotel. The lower exit may be a little bit faster, but if you have luggage, you may wish to take the upper exit, otherwise you'll be lugging your luggage up some stairs.
There is a discount supermarket next door (Lidi), which is open from 8 am - 8 pm (closed Sunday).
Breakfast is served in the basement and consists of various cold cuts, breads, yogurt, fruit cocktail, hard boiled eggs, cereal, cheese, OJ/Apple juice, jams, variety of teas and coffee.
There is a couple of Internet terminals in the lobby (20 minutes for 1 Euro).
The only minor drawbacks were that the lobby/elevators were a little bit smokey and the staff could have been friendlier. Overall, the hotel s definitely an excellent value.
