Really nice, clean, and modern "hotel apartment" in a quiet area. It is about a 30 minute walk to the old town and city center, and fairly close to bus stops and metro stations. Lots of nice little cafes and such nearby too, I recommend the bagel place for breakfast.
The only drawback, if you are the type that likes it cold at night to sleep you may find it too hot at night in the summer, as the windows don't open and while there is AC, you can't control the temperature of the AC from within the apartment.
The rooms are also pretty dark which is great at night but not ideal if you will be spending a lot of time during the daytime in the room, I imagine even more so on the units that have no windows (ours had windows though). But if you plan on mostly just spending your evenings here it is not a problem. It is a 'basement apartment' after all so this is to be expected.
It felt a little strange being in what feels like a hotel but with no reception most of the day. However as they state, this is what makes it an 'apartment hotel' and part of how they are able to keep the cost of the rooms down. Everything is automated so check in and check out were very easy.
All in all this is a really nice apartment/hotel and I would recommend it, host is very friendly too. Great for those who want to spend their days exploring Stockholm and wanting a nice quiet place to stay at night.