I've got the whole TANKS! series on DVD. Not too bad documentaries, but they arent the best either. Their biggest flaw is that they are just too long and repeat same things you have already heard and learned about either before watching the documentary or during the same episode. Episodes are too long for my taste as when it starts getting dangling to very small details, it gets very numbing. WaW for the win.
It is not a bad series (same goes to the whole BATTLEFIELD series) but the episodes (which afaik were supposed to be in episodes when viewed via TV, but in DVD they are just one long episodes) are way too long to keep the interest up from start to finish.