Does Agfa still make APX 400 in 35mm? That is my recommendation for lower light levels at night or in historic areas. The very recent (post-unification) urban spaces in Berlin are very open and bright. For general daytime photos I would use Agfa APX 100, a good film that should be readily available. And of course EFKE 25 or Adox KB 14 if you want some really fine grain negatives. Do you plan to process all of your film while you are there?