Let's make this clear: I love Merlin, and thought series 3 was splendid. So as far as the episodes go, I have no complaints, and the box in it self is beautiful.
But, here is my complaint: the extra material, or more exactly, the lack thereof. Hardly any audio commentaries (and no Colin & Bradley-ones which are my favourites), no "magic behind merlin" (as there was no such show this series), none of the material that was available on the homepage during the series such as Colin and Bradleys 13-episode "quest". Why!? For BBC's second largest family show (after Doctor Who) they should really put a bit more effort into the box sets.