The collection is great, the picture and sound quality is above average but not perfect in case of the first two parts. But I think that this relies on the fact that the two movies are quite old so that the technique wasn't best at this time. So this doesn't conflict my rating.
I like, that the first three movies got German audio dubbing and subtitles, so it is possible to view the movies in English and got the German subs for understanding help if the speech is hard to hear. And here comes the reason for one star missing: the last movie, Phantom Protocol, doesn't have German dubbing and subs. So normally the rating as English customer would be five stars! ;-)