I only noticed one of the actors/characters mumbling ... DH and I usually help each other out with interpretation because invariably one of us has heard what was said! Or, I just make it up so that he doesn't pause and rewind It is quite gory but not as bad as The Young Doctor's Notebook which had me watching between my fingers. I accept it as a story of those times, and I love the authenticity of the sets. Barrow I think you're right, it is the Morse template in another era.
I find elements of Call the Midwife upsetting, e.g. the fact that women were often destined to get pregnant year after year and had no or very little control over it. Give me a murder to try and solve any day. When it gets too gory, I can always focus on my knitting for that moment!