I had a super tiny single room but it was for me (am a tiny girl too) perfect as I just wanted to have a shower and drop into bed as I needed to get up all too early again. I arrived very late after midnight and the check in with codes worked perfectly. Breakfast buffet was surprisingly good. I will definitely come back next time I travel on my own to Stockholm and just need to crash for the night. Soooo much better than a hostel.
Ps. If you have a lot of luggage perhaps not the best as it is small. I just had hand luggage