I had a great time at Kasia & Alan's apartment! We stayed with a group of 4 girls and the apartment was perfect for just that. It is very easy to get to by train, a great location to be during a city trip since you're in Mitte within minutes. We had to arrange our check-in through a check-in company that you have to email and call in advance, so be aware of that! Kasia and Alan left a folder with some nice places to check out during our stay, which was great. I would defenitely stay here again!