While the writing in particular is superb for this series, along with equally great acting and filmmaking, delivering characters who from the start are well-drawn and possessed of depth beyond the thickness of the screen, the DVD set of the first season is lacking in some regions.
Given that someone interested in purchasing the set is already surely a fan of the show, I will not go any further in my praise of the cast and creators. However, there is only one episode (the Pilot) which has a commentary. While it is provided by the show's creator, Donald Bellisario, there are a number of great episodes in this season which I would find a commentary suitable. There are three short special features on the sixth disc, mainly dealing with the process of casting the characters and developing the show. Another significant flaw in my opinion is the lack of subtitles. The description of the set here on Amazon notes that the discs are subtitled, but this is not the case (neither the setup menu nor the subtitle button for my player gives the option). Also, to watch the episodes, you have to select each episode on the disc individually; there is no "play all" feature. I like to see the menu once only until I've seen the entirety of the shows on the disc.
Still, the menus are not overdone with annoying transitions between screens like some movies and shows use, and the quality of the video is at least as good as the original broadcasts. I recommend the set for those who are fans of the show, but for those with hearing difficulties who want subtitles, this set won't suffice.