You may also consider another hotel in Krakow, quite near Eden. It is called Kolory (Colors). Check their web page:http://www.kolory.com.pl/onas.php?lang=EN
I stayed there during the Event. The rooms are not very big, but air-conditioned, and the breakfasts are really good - French style.
They also speak quite good English.
Both of these hotels are located in Kazimierz - the former Jewish quarter of Krakow, quite near the city centre.
As for Berlin - the hotel I like is called Etap - situated near Potsdamer Platz - almost in the city centre.http://www.accorhotels.com/gb/hotel-505 ... ndex.shtml
Nice budget room price, major attractions are within walking distance.
If you have any questions, especially concerning Poland, don't hesitate to ask.