As a home viewer, it's rather annoying to sit through 35 minutes of actual content per 42 minute episode with breaks for adverts not present on the DVD every few minutes. Most of this set could've done with a lot of editing to get rid of content rendered unnecessary by the format change; for example, leaving aside the adverts issue as I've covered that enough, someone who already owns the DVD does not need to see the series trailer at the beginning of each episode.
Fortunately, it is not all doom and gloom. The episodes are genuinely interesting, especially the "Brooke Shields" one as mentioned above (if I recall correctly, she can trace her father's lineage back over 700 years through aristocracy and kings). You can also observe how documentaries are made, as the show is fairly transparent in that it picks celebrities who have connections to difficult times in history, such as World War II or the American Civil War so they the episode will basically be about that time period rather than the celebrity's family history. A notable example of this is that you get two episodes ("Emmitt Smith" and "Spike Lee") whose entire running time can basically be summed up as "slavery and racism are bad". However, although it is transparent, it still works and is fairly emotional.
I should mention that the DVD feels very basic. It is the series and only the series. There's no special features of any kind here, and as I said, it hasn't been edited down from its original television airing (which is a bit of a rarity in my experience). I have a strong suspicion that all the producers did was ship over the original footage without the added adverts, which was then put as is ontoDVD.
Overall, it's a fairly average documentary. If someone asked me whether I would recommend it (this is the point of a review, after all), I'd have to say no. Usually a DVD or Blu-ray offers both an experience you cannot get on the television and a chance to actually own your favourite shows to watch whenever you like. In this case there is nothing you can't get watching it on television, and to be honest, this isn't one of my favourite shows. If you're a fan of the series, then this is probably for you (although if you want to learn anything about how it was made I wouldn't bother). Otherwise try and catch an episode before you buy it.