North Hotel is right on the Reeperbahn, so if that's where you want to stay, it's perfect. There are clubs and bars and (seemingly harmless) homeless people right outside the hotel, but the window seals tightly and shuts out the noise. The rooms are small, but clean and functional. The staff is friendly and helpful and speaks decent English.
Late check-out (11 AM) is not allowed, though they will store your bags for you. However, they don't have storage lockers.
We recommend avoiding the first floor as the room they originally assigned us (101) was so small that it had no room for two suitcases to lay open (without putting one on the bed), nor did it have air-conditioning, which is important since opening the window for ventilation at night would make it hard to sleep due to street noise. Luckily the staff was able to switch us to the 2nd floor, which was slightly roomier and had A/C. We had a comfortable stay.