For what it's worth, I'm going to say that for me the series started to get weak from this point.
Just my own opinion, you understand.
I found the interior scenes shot on film depressing - looks good on feature length versions, but not very TV like. IMO.
I found the series to be too reliant on secondary characters, particularly with the re-introduction of Jean Alexander. IMO.
I also found the series was becoming very samey, and the structure of each episode, particularly the 'early morning' scenes, repetitive too. IMO.
The show was still ok though, but it had changed IMO.
The show stuck to this format for many years from this point.
I like Camera Shy and The Phantom of the Graveyard best.
Like Series 8 and Series 13, the Christmas Special was neither long or Christmassy, so it's a little surprising they are referred to as specials.