I just stayed for a night after meeting some friends for an event in Clapham. The staff were very friendly and the pub looks like it would be a good laugh - I wasn't there to see it at its best, sadly!
The room, a 3-bed shared dorm, was a single triple bunk bed in a very small room. The (mixed) shower room was a bit rough around the edges, and could really have done with a thorough, daily clean - it certainly didn't look like that happened. The shower door in mine was hanging off the hinge too, but wouldn't have taken much effort for stuff to fix properly.
My biggest gripe? No security. No locker or cage-box to be able to put my items in and secure with a padlock. I've stayed in many hostels, and that's something that should feature in them all.
The hostel is actually quite close to being decent, especially for the location and price. It just needs a bit of TLC!