The PDF version of Doctor Who: Adventures in Time and Space Limited Edition Hardcover Edition is now up at DriveThruRPG.
If you have either of the 11th or 10th Doctor version of this game then you have most of the rules and text, though some things look like the are a bit clearer (or I am rereading them for 10th time). This is one full document as opposed to the multiple PDFs of the "boxed sets". It also updates the text to reflect the last bits of the Matt Smith seasons and the Day of the Doctor 50th Anniversary special. So stats for the War Doctor and updated Zygons.
It is an extremely attractive book (256 full color pages). If you are new to this game then this is the place to start. If you are new to Doctor Who, well then I would say grab the Tenth or Eleventh Doctor version of the rules. All the same rules, but less emphasis on the the show's own history. Though there are the story/adventure seeds for all 12 doctors and that is very nice.
I plan on picking this one up in hardback as soon as I can to be honest. That's how much I enjoy this game.