We bought this DVD for our 3 1/2 year old boy who is in the advanced stages of dinosaur obsession. He is very interested in all the particulars of each dinosaur -- names, diet, chronology, habits, etc. He was beside himself with delight when we first started watching the DVDs, literally jumping up and down yelling "Coelophysis! I love this! Diplodocus! Look, Allosaurus!"
As almost all others have mentioned, the overall production design is beyond impressive, and beggars the word "clever." Witty, thoughtful, convincing, and highly entertaining.
Unfortunately (for us), there is one dramatic trope that appears in literally every episode of this and the later "Walking With Prehistoric Beasts" series: eating babies. Sometimes creatures eat their own young for murky defensive reasons; sometimes predators pick off defenseless baby prey; sometimes territorial males eat their competitors' babies; sometimes giant ants eat cute hatchlings.
I can't fault the dramatic effect of these passages, and the continuing theme that competition is the engine of evolution is accurate and effectively presented. But it takes the air out of my little boy's enthusiasm when he constantly expects the cute baby dinosaurs to be messily devoured, and it makes me grimace to watch him watching it. Those scenes are not especially suspenseful, and don't seem to agitate him (he got a lot more anxious at "Finding Nemo"). But when his reaction to two Allosaurus eating a baby Diplodocus is "look, they're sharing!", I decided the infanticide just wasn't age-appropriate.
We put the series aside for now, and maybe we'll take it up again in a year.