Davide was very helpful during booking and check-in process- was all a very easy process. The apartment is only 10min walk from the central station so it's very convenient for airport/regional trains. Very easy to walk pretty much anywhere in the city from the apartment and is in a great area with a huge amount of cool restaurants, bars and cafes nearby as well as supermarkets.
Flights of stairs weren't an issue for us. However, we were a group of 4 and I would not recommend this apartment for any more than 2 people comfortably. We were incredibly cramped for our short stay, luckily we're a close group! Apartment wasn't overly clean when we arrived and it was a little low on amenities- toilet paper, washing liquids etc.
Loved Copenhagen but would only recommend Davide's place for a smaller group.