Sporadic W.
Yelp
I stayed here for a couple days by myself when I visited the country in May of 2013 with the intention of seeing and exploring the Giants Causeway, Carrick-a-rede rope bridge, and Titanic's museum & dry dock.  I saw that and more!  
The hostel was more expensive than some other hostels in the area, but much better in terms of satisfaction via safety, comfort, and style/vibe.  Vagabonds exudes positive, chill, laid-back "good times" vibes.  Staff is on-site 24/7.  
The staff is super friendly and chat you up after your day, expect to have a conversation about your day, where you're from, where they're from, life experiences, suggestions about places to check out.  One suggestion they gave was to do the Black Cab tour, and if I had more time and money, I would have definitely done that one.  It's a socio-political tour where the driver talks to you about the country's history and the civil war, shows sites, etc.  Getting back to the hostel and staff- if you just want to go in your room and be a loner, this is not the right place for you.  The staff cares, wants to converse and help you out!  The staff creates a schedule and takes people out at night and during the day.  I wasn't there the day they were going to St. George's market (I love local farmer's markets), but have heard great things and wanted to go.  Maybe next time!
The rooms, I chose to stay in an all-female dorm since I was traveling alone.  One night, all of the beds were full and the other couple nights it was me and 2 others.  I stayed in a 6 person/3 bunk bed room. Rooms were tidy and clean.  There is plenty of storage underneath the bunk beds for storage and also lockers in the room as well.  Linens and blankets are included in the price!  They are decorated with a funky cool twist, meaning different quotes, paint choices, and art work adorns the rooms, hallways and common rooms.  Bathrooms are shared spaces, meaning they are not communal, however you may share the room that holds a shower and toilet with several rooms.  However there are several single shower and toilet/sink rooms per floor, and some rooms just have a toilet and sink combo.  They are kept fairly clean considering they are shared amongst several people at any given time frame.  With that in mind, I only had to wait about 5 minutes one time to use the shower, all the other times the showers and toilets/sinks were vacant.  
Kitchen and free breakfast.  The kitchen is nice, you can store your own goods in the fridge/freezer and cook anytime.  The hostel does provide free breakfast in the mornings, which is a nice feature.  I helped the staff set it up one morning when I was up unusually early.  The breakfast options are several kinds of cereal, milks, juices, toasts, butter, jams, teas and coffee.  Pretty basic, but definitely a welcome touch for a budget traveler, like myself.
Now the only issue that I had was not really with the actual hostel, but just with the location.  After I found out where it was, I didn't have any issues locating it for the rest of my trip.  Initially, I thought it would be easy to find, however after walking around what seemed to be all of Belfast and gaining the help of several locals and university students, I got a bit nervous and frustrated since it was getting late and I was still walking around unable to find it.  Note: There are SEVERAL streets named after the Queen... Queen Street, Queen Road, Queen Boulevard, etc.  and I swear I walked on probably 8 streets with Queen in it, looking for Vagabonds.  If I remember correctly, that is the cross street with University (several hostels are located on University too.. not sure if several University streets too or not.  Only one other hostel was relatively close-by to Vagabonds, the others are much further.  Look at a map and the cross streets of this hostel before setting off to find it.  There is a pretty church across the street that became my landmark (I will post a picture of it).  
From the main bus terminal, it is a straight shot/ about a 20 minute walk at a medium to brisk pace, so it's definitely walk-able.  There are taxis lined up outside the main bus terminal though, so if you want a ride there are plenty of options.  One time, I took the city bus to get in out from the rain, but walking is just fine.  I traveled light and with a small budget, so I didn't mind walking.  NOTE: Weather changes often in Belfast, so bring a light jacket/rain coat, sweater and sun hat.
If I'm ever in Belfast again, I would gladly stay at this hostel!