Overall- good location, wi-fi, kitchen, breakfast and lockers were all great. On the down side was general cleanliness, bed bugs, number of people to a room and awkward showers/ toilets etc.
The location is really good, walking distance from everything I wanted- train station, beach, old town, galleries etc. It's right behind the main shopping centre and there's a big Monoprix supermarket right round the corner.
Cooking facilities were good, there's a microwave and some hobs, plates, cutlery etc. There's a big fridge for storage but not cupboards for dry food so you'll have to keep that in your room. There's no oven. The kitchen is not open for use in the morning but they give you breakfast of cereals, bread with spreads, orange juice and hot drinks.
The hostel is closed 11-3 for cleaning but this wasn't a problem for me as I was out exploring during the day. If you were on a longer trip and needed a day to rest it may be a problem.
The rooms were quite crowded, mine had 7 beds and there was not enough space for everyone to be doing stuff at once. The lockers were big enough to fit my carry-on size suitcase so I locked mine in there with my own padlock. There's a little pouch for nick nacks and a reading light at each bed which is great, but only one socket between 7 for charging things. There are, however, more sockets downstairs in the dining areas.
Free wi-fi was very handy but don't expect a strong signal if you're in your room.
The shower is in the room and was basic but fine. Just watch for your stuff getting soaked. There are two sinks in the room with annoying push taps that my roommate pushed about 20 times in a row every morning at 7am. The toilets were outside the room with no sinks, just hand sanitiser. Not very hygenic. You have to go back into your room to wash your hands and even then you'll need to have brought your own soap.
My room had bed bugs. Unfortunately it's to be expected in most hostels and hotels (and cinemas and department stores!) but just unfortunate that I got bitten every night. I had to wash everything on hot as soon as I got home and fumigate everything that couldn't be washed. It was very unpleasant to go to sleep knowing I'd get bitten by insects but you will be hard pressed to find a hostel that has never had them.