This is a fine hostel. Yes, the triple-decker bunks are a bit tight, and my last night it was a little warm. It's not right in the center and is inconvenient for the tube, but the 87 bus stops literally right in front of the hostel and that will get you to trafalgar square in about 25 mins, and for only £1.50 a ride it's not a bad deal at all. The breakfast is basic--toast, oatmeal, tea/coffee--but tasty and free. I lucked out with early-to-bed, early-to-rise roommates, but of course these things vary with hostels. Never had a problem waiting for the bathroom or showers even though they're shared, which was a pleasant surprise. The wifi wasn't great in the rooms but it's fine to go hang out in the pub to go online, there were always seats available even though I was staying here over a weekend.
You need your own lock for the locker (they sell them if you don't have one) and your own towel. This isn't abnormal for hostels so if that's going to make you miserable then be sure to check before you book one! The pub was nice and clean, and there was a quiz night going on when I checked in.
Plus, it was hella cheap. I feel like I got my money's worth.