In September 2009, I stayed one night at the Pickwick Hall hostel. From the moment I stepped foot into the hostel, I was entrenched in this awful smell of Indian food (or something).
The room I chose was shared with five other women and was of decent size, but it could have been bigger. While the sheets appeared clean, they were obviously stained and burned in some sections. All in all it really wasn't a bad night of sleep.
The bathrooms were pretty disgusting. There was mold growing on most surfaces and there wasn't really any space to place your clothes while you showered. However, I could tell that the bathrooms had been cleaned. There were two computers available for guests to use and access the internet, which was nice, even though the connection was really slow. Breakfast was free but minimal. The location of the hostel was right in the heart of London, but there are far better places to stay in London for the same price.
I would look to stay elsewhere next time I visit London.