They'r worth listening to, Dolce: apart from the weirdness of PG singing in German, parts of PG III and the whole PG IV have been remixed, sometimes with great effect as in Kiss of Life - Mundzumundbeatmung, as Rena wrote.
Funny 'Who Gives a Shit' (TM) :-] moment (like Codiglio always says, you know him Dolce

) : when I first found the two German Albums - in France, because nobody had them in Italy at the time - looking at the titles I always believed that "Mundzumundbeatmung" should be divided into "Mundzum und Beatmung", like they were two characters or something, so I kept wondering who the hell they were and why Peter was singing about them. :-]
It took a schoolmate of mine who knew German to translate that title in the right way, Mund-zu-Mund-Beatmung = mouth-to-mouth breathing, which is the actual theme of the song.