I've never been to Berlin or Dresden. But the Germans (from all over the country) that I've heard speak (in natura or on TV) certainly don't use the fricative more often than the (short) trill – even if only because in the circumstances where a Parisian would use the fricative, most Germans would use a vowel instead. In French, both fricatives do occur, but I'm sure  occurs more often in front of a vowel than in front of a consonant or at the end of a word sentence! 
 :::::::In Austria or Bavaria people never use a uvular fricative and find them, especially the voiced one, quite difficult to pronounce. That includes myself – and in Austria this is considered Standard German, as used by radio and TV newsreaders. 
 :::::::There are, however, languages where the trill has been replaced by a fricative on a wide scale. In Dutch the fricative is standard and the trill is dialectal. Danish – geographically between German and southern Swedish, so expected to have or once have had a uvular trill – has some peculiarity of its own; Danish language says it's the uvo-pharyngeal approximant, Danish phonology says that word-initially it's the voiced uvular fricative, and something else I've once read even said it's a pharyngeal trill! 
 :::::::David Marjanović | david.marjanovic_at_gmx.at | 13:30 CET-summertime | 2006/3/31