We had to open the window because we were hot (even though it was not a hot day), but being next to the railway line meant we were therefore woken up by trains a lot. So maybe some air con would be a good idea.
It's probably the best hostel I've stayed in in London on the whole, especially considering the price I paid (very good value). Modern, clean and spacial.
As I didn't pay much for the room I'm not overly complaining, and I have seen worse hostels, but this was very cramped in both the bedrooms and the kitchen, and I haven't decided whether to blame the hostel but the rooms were absolutely boiling (I acknowledge that it was a warm day), meaning I got very little sleep. Overall though, not too bad for the price we paid.