We really loved staying at the Helmers. It is essentially a home with three different rooms. The management was great to work with and gave us some excellent tips for exploring the city. Only downside was the noise on the first night. We stayed on the bottom floor, and the people staying above us were very loud, and the sound carried throughout the house. Other than that, I would highly recommend staying here.
I'd definitely recommend staying at St Christopher's. The staff was more than willing to help us out with any travel concerns. I also liked the restaurant/bar that was located on the first floor (food was actually really good). The hostel provided free breakfast from 8-10, and it was much better than some of the other hostel breakfasts we had received during our trip. The room was relatively clean. I would have liked to have wi-fi in the rooms (only available downstairs). The location was great.
I didn't enjoy staying at this hostel. It was very loud and the staff seemed unorganized. There was breakfast offered for 5 euros, and it was awful--if you end up staying here, don't waste your money. The rooms were dirty, and the towels smelled like mildew. The bathroom was disgusting--urine constantly on the floor. The location is on "hostel row" in Munich, so can't really complain about it. I think if someone is looking for more of a party-type hostel, then maybe this place would suit you.