I fully recommend taking the bus from Berlin to Prague. Not a train. The bus. I think it cost €15, included a plush leather seat all to myself, offered movies, was super clean, and provided free hot chocolate. It was a fantastic travel experience. Prague is awesome. The clouds seem different there. Puffier and with cool dark purplish colors. Architecture is supacool. I think my accommodations merit a mention.
My room had a giant bed and another bed, which seems like a stroke of luck — maybe they were out of rooms in my discount hotel. The room offered wall art:
:)
The buildings were like so (like Budapest and Vienna):
and like so (the Národní museum):
More on the castle soon!