It's a hostel and a hotel in one, which makes a mixed atmosphere. The kitchen is big and nice, if not always very clean. Four-bed dorms are on the small side and not particularly comfortable, especially the upper bunks -- the ceiling is too low and the steps are difficult to climb. No lockable lockers in the dorms, which is a security concern, at least for me. Houses a lot of students looking for a more permanent accommodation.
I have been to many hostels in Stockholm and this is probably the best one in most ways. However, it has a an emphasis on social life and would probably work best if you're interested in meeting tons of people. It also tends to attract a younger crowd. If you just need a place to sleep, this might not be optimal for you.
There is no real kitchen, only a single microwave oven, kettle and a single fridge. The kitchen that used to be there has been turned into yet another dorm. Otherwise, it's reasonable if you're on a tight budget. The 10-bed dorm has no windows unlike the 12-bed one, so I would recommend the latter of the two.
I stayed there for one night in a six person dorm. It was fine -- the location is really good and it's exciting to stay on a ship. It's also very clean and there is tons of (very private!) toilets and showers. There isn't much of a typical hostel atmosphere, which might be a good or a bad thing. The loud music on the deck (there's a restaurant) can bother a bit. Wifi could be faster. I never used the kitchen, so I can't comment about that.
I have stayed there a couple of times. It is clean and modern and the kitchen as well as the common area are good for meeting people, if that's your thing. The dorms are also pretty spacious. Wifi in dorms could be faster. Kitchen's good and there's plenty of fridge space. There's, however, little privacy in toilets and showers. My general impression was that it is more tightly regulated than most other hostels. I don't know how much the rules are actually enforced, though. Would recommend.
I have stayed there a couple of times. Some major problems. Nearly everything seems to be dirty and in disrepair. The fridges are disgusting. Wifi works only if you're lucky. There are no lockers in the rooms to put your bags away, so either leave your stuff at the reception, leave it under your bed and hope it won't be stolen, or carry it around with you. Showers work to varying degrees and there are too few of them. The breakfast is a unique thing, though, and there's plenty of space.
I lived there for a week. It's mostly all right, and reminds more of a hotel than a hostel. I had my own room (very sparse), so I don't know about the dorms. The fridge in the kitchen has separate lockable boxes, which, however, are rusty and not very hygienic. Cleanliness is a problem in other areas as well. The worst thing about this place is that the wifi is of very poor quality and costs ridiculously much - it's the only place I've stayed where you have to pay for Internet connection by day.
I really liked this place - it is comfy and the location high up means there is always fresh air. I would have stayed there longer, if it wasn't for bedbugs -- hopefully they have sorted this out by now. My main other complaint is that the showers and toilets are too few. It could also be cleaner.
I have stayed at this place many times but only in the dorms. It's all right for the money and the location is good. A peculiarity of this place is that there are some people basically living there - they have stayed there for months or even years (!). Beware that since the owner changed, there is basically no kitchen anymore - it was turned into another room. There is only a single microwave and overcrowded fridge. Some showers are broken and it's not very clean. The wifi speed is excellent.