The location of the apartment is fantastic, but there are a few things to keep in mind before booking. Unfortunately, the communication prior to us arriving wasn't great. We informed the agency in charge that we would be arriving after midnight and they kindly told us that a self-check-in option was in place. When we arrived, the instructions turned out to be incorrect. After a few failed attempts, we tried a few random numbers from emails they had sent previously and finally managed to get into the building. Make sure to arrive during the day, so you don't have the same issue... During the day, the contact person answered super quickly.
The apartment is spacious and clean and within 5 min proximity of the Duomo and public transport options to the rest of the city. It's a wonderful starting point and makes it easy to quickly come home while exploring the city.
However, the nights weren't great. Each night, we've only slept for around 3 - 4 hours, which was mostly due to the garbage on the street being collected 4 times a week and sometimes even 3 times a night by a massive waste collection vehicle! They come at random times, sometimes at 3 am, sometimes at 6 am and despite having the windows closed and stuffing our ears with earplugs, it still felt like trying to sleep next to a starting airplane. A warning in the description would have been kind. Luckily, caffè for 1 euro at every counter does do the trick and we still had a wonderful time in Milan.
Apart from that, the mattress is quite soft and cheap, so don't expect a really comfy bed, which is of course fine for the price we paid.
Again, the apartment's location is great, but it's also its downfall, because of the noise in the night.