I spent four nights at Pension Peters in November 2012 and I recommend it.
I arrived at about 7 pm. I was notified that the office is not open after 6 pm and my key will be held at Hefner Bar, in the same building as Pension Peters. That took all of one second. However, I could not find the right door and it was raining lightly. Some guests of the Pension saw me with my bags and guided me inside.
The room was basic but everything worked. I especially appreciated the heated towel rack, for drying clothes. There is no air-conditioning, no phone, no elevator and the clock on the TV was not correct. The internet connection is interrupted frequently. The room door is a double dead bolt. Lighting for in-bed reading is good.
The highlight was definitely the bountiful breakfast. There was four kinds of cold cuts, cheeses, yogurt, excellent bread, scrambled eggs with juices and coffee.
The staff could not have been more helpful. Pension Peters supplies guests with their own map of Berlin which shows Berlin in different scales, the immediate vicinity, the area and the city. They guided me to take Bus 100 and 200 which covers the main tourist spots and can be taken from nearby Zoo Station. Currywurst is the national dish. At Zoo Station 2 sausages, french fries with mayo, 4.7 euro. Beer 1.6 euro.
The area is full of restaurants. Across the street from Peters Pension is Dick Wirtin, an old Berlin pub. The breaded pork chop is huge, with mesh potato underneath, plus a cucumber salad, 11.90 euros. The Konig Pilsner is 3.2 euros for 0.4-liter. Terrific place. There are several 'supermarkets' which is the size of convenience stores in the US.
An S-bahn station is about 150 meters away.