I'd rank this series so far:
1) Cold War
2) The Crimson Horror
3) The Bells of St. John
4) Journey to the Centre of the TARDIS
5) Rings of Underrated
7) Nightmare in Silver
Enjoyed 'em all though to some extent. Just odd that Mark Gatiss has kicked arse while Neil fucking Gaiman delivers the weakest offering.
I agree with Cold War and Bells of St. John, why on earth does everyone like Crimson horror so much? Was appalling.