I would definitely stay at...

Liked: Hotel was in an excellent location for exploring Kreuzberg and the City sights.
Disliked: Only small complaint was that the shower in the room wasn't overly warm/hot.

Very poor

Good bang for buck

Liked: The hotel room was clean, everything needed was there. The breakfast was very nice for 10 EUR

Good

Liked: Conveniently located near Kotbusser Tor and two other U-Bahn stations, it is in a great location for airport drop-off and then seeing Kreuzberg and the rest of Berlin. Hotel is much cleaner and comfortable than its exterior would suggest, making for a comfy stay.
Disliked: My room backed onto an area that was a touch noisy early in the mornings with birds and people getting around. The facilities state that there's a 24 hour reception, but it closes between midnight and four which made it a bit awkward as we had an early flight and just had to leave our keycards outside the reception door.

Exceptional

Liked: The beds were very comfortable.Big space in the showerWell located.

Very good

Liked: Good location in Kreuzberg neighborhood and just 50 yards from Schonleinstrasse metro entrance. Popular younger crowd area. LOTS of many different restaurants. Saturday outdoor market 200 feet away by the river. Typical German breakfast spread. 24/7 desk. Elevator!! Not a high end neighborhood by any means, but feels safe at night. Good Market across the street.
Disliked: Smallest shower (room 505) I've seen in 10 months of traveling Europe. If you're BIG, forget about it!Nothing to see here, except the swans in the river under the bridge.

Decent, would stay again.

Liked: Clean, spacious, nice bathroom, decent breakfast.
Disliked: Very expensive for the neighborhood. Elevator goes in between floors, limited toiletries.

Exceptional

Liked: Kind staff, good position, clean and confortable rooms.

Very good