These specials not only were there to give Tennant the send-off he so rightly deserved, but also to help the series runners manage the transition to a new head-writer, as well as casting a new Doctor.
But by the time of the seventh episode, "A Good Man Goes to War," the quality storytelling had won me over and I was totally hooked into Moffat’s vision. I saw how terrifying it is when the light-hearted man turns deadly serious.
That's a lot of extremely inventive television and I didn't even mention the episode written by Neil Gaiman, "The Doctor's Wife," which is one of the high points of the show's Forty-Nine year history.