The apartment is well situated near the city center, just a few blocks from the river banks. However, it could be quite noisy at night, especially at the weekend as there are several bars/pubs around. So if you are a light sleeper, don't forget your earplugs. Otherwise, it is a lovely spot to get rest after a day of exploring the city. and we felt very comfortable there.
There was a minor issue with our check-in (we were missing clean towels and bedsheets at the time of our arrival at 3pm), but the communication with the host was prompt and straightforward and everything was fixed quickly. If we had arrived a few hours later, we wouldn't have even known that the cleaning service run into some problems and was unable to finish the job before our arrival. So in the end everything worked out well.
The self-check-in is like some kind of an exit game (more like an entrance game) where you need to solve few puzzles to get the reward (keys in this case), but if you read the instructions carefully and look around, you will figure it out :)