I stayed for 5 nights in June, and it was like a 'home away from home'. The staff are all volunteers, and couldn't have been more helpful or generous with their time.
The rooms are basic but very comfortable, it's likely you'll have to share with a couple of other guest. The shared men's bathroom has just been refurbished to a very high standard.
Breakfast is a fantastic spread, which includes home-made muffins or biscuits. If you have to leave before 8am they'll put out a 'early' breakfast for you. In the evening you're invited to join for tea and cookies at 9pm, which is a really wonderful way of meeting fellow guests.
The Guest House is about 30 minutes north of the city on the bus. The bus stop is no more than 2 minutes walk from the house, and I found that it was very easy to get around the city. The staff are also very happy to provide you with maps and timetables if you need them.
All this for just $40 per night. I would have paid $80 and still considered it a bargain!