The location is far. You will have to take the DLR to get into the middle of London - which is an extra 6 or so stops. Not convenient. The area is very quiet, not much to do. Staff is very nice and helpful, but the 6-bed female dorm that I stayed in was terrible! So small, and only one incredibly small window in the ceiling above my bed. So so so hot and stuffy in July. And when it rains and you have the window open, it rains right into your bed. Cheap, but would not stay again.
Overall a great st Christopher's location. The staff is nice and the bar is usually very lively - lots of opportunities to meet people :) laundry is easy, and it's mostly a very clean hostel. Only issue is the number of Mosquitos.... Sooooooo many. Stayed there 4 nights in July, think that I got 10 Mosquito bites. Nothing you can really do because it's close to the canal. Nice stay- pricier than hostels in other places but everything in Paris is a little pricier.
The place is very small and the location is not the best near gare du nord. That being said, there is a little area to make food and you can hang out downstairs. Wifi is pretty bad, and it is very loud! However, the staff is unbelievably nice. I probably wouldn't stay again because it is not the best location and because it is loud, but overall a solid hostel.