I've stayed in this Youth Hostel quite a few times now. It's right next to Saint Paul's cathedral (I love the sound of the bells chiming the time at night). But that in itself isn't why I go back. My main reason is that, as London Youth Hostels go, it's not a "party hostel." There are plenty of young people there, but plenty of families and older people as well, and I'm well past being able to tolerate drunken clubbers bursting into the dorm at 4.30 am, turning on the light and conducting a voluble conversation in Spanish until 6.30am. This is not to say it's always quiet (you will still get the odd 19 year old who is convinced that the rest of the dorm loves listening to his personal stereo at 1am). As one other reviewer says, you get competition for power sockets in the dorms (but I can tolerate that). Breakfasts have grown slightly more spartan over the years as well (from bacon, eggs and beans to bacon, egg and bean) and the place is shabbier now than it was in 2001, when I first went there. On the other hand, it's relatively close to the places I like to go in London (40 minute walk to the British Library or British Museum; 35 minute walk to Trafalgar Square and the edges of Soho; 20 minutes to Covent Garden Market). And, as I say, you can't really get more London than Saint Paul's.

It is amazing that you can stay so close to such an historic landmark as St Pauls. The hostel is old and there are not a lot of bathrooms (typical english haha) and you have to pay for breakfast (not unusual in England) but it is worth it as the hostel is so central. A short walk to the Millenium bridge and then a stroll along the South Bank to the Globe Theatre and Tower Bridge.

Although I enjoyed my stay, it had its ups and it's downs. The beds were comfortable although to get to the top bunk you had to climb over the lower ones. There was only one plug socket in our room, leaving 6 people in a room to charge their phones in shifts. The breakfast was good though-a buffet with cereals, croissants, fruit, and full English. And the service was good. The protesters were camped at the top of the road but were no problem, in fact they were very approachable and it was interesting to hear their views.

I've stayed in better, I've stayed in worse. The St Paul's YHA is an average basic hostel. I found the bathrooms and rooms to be clean but they definitely are not the most up to date in terms of furniture and carpets.
The location in London is amazing, the building itself is gorgeous, and there lots of attractions and restaurants nearby. Two things to keep in mind: There are no elevators, St Paul's Cathedral does not operate with courtesy hours (if you're a light sleeper this might not be the place for you)