TLDR; Awesome location and balcony, but a little bit worn.
The location is really great, next to torggata with lots of bars and restaurant, and close the the hip grunerlokka. The neighbourhood is a tiny bit shady, but nothing to worry about at all during daytime.
The building is a bit run down and not well maintained. Awful smell in the entrance, broken tiles in the elevator, washing machine left in the hallway.
The apartment itself is great. All amenities you need. Nice views. Large TV.
It's a little bit worn and torn, and should have been maintained a bit better. For example a floor to ceiling window in one of the rooms was broken, so it was not possible to close it properly and ended up blowing open.
The balcony is awesome if you are lucky enough to find yourself in Oslo on a nice sunny day. Lot's of chairs to sit on. But only old ones that were quite worn. Some new outdoor furniture would have been great.
All in all, it's a great place to stay. Awesome terrace. Awesome location.