Thanks, that's already a lot better (placing the -density option before the source file name seems to have caused the major improvement).
Yet, I'm not really convinced of the quality that can be achieved that way. Maybe I'm little picky in these things, but I still feel the text looks a bit ragged, and the graphics don't seem to be anti-aliased at all (I also tried putting -antialias in various places — couldn't see a difference, though). In other words, I can't help thinking that the results of running gs separately somehow look better (the version on the right in the side-by-side comparison (300%-zoom, cropped)) — at least smoother. Anyhow, I guess I'll stick with my technique for the time being.
PS: Große Vallüla ??? xD
Yeah well, that was the first adequate PDF file I found in my temp directory. Rest assured, I have no affiliation with Maria & Margot, or that kind of music, whatsoever ;) — I just like hiking in the mountains.