I stayed at Bart's place for 5 days during a stay in Warsaw. Bart (email hidden), meeting me at the nearest station on arrival and staying in communication with me throughout my time. He couldn't have been more helpful and even lent me a Polish mobile phone during my time there so that I could avoid international charges!
The flat is really excellent - immaculately clean and tidy, well-appointed, completely modern interior and with plenty of space for two or so guests. The area is quiet and you quickly pick up how to take public transport to the city centre. I would happily recommend Bart's apartment to future Airbnb'ers!