Things that did bug me: film grain in Sins and Inner Light. Just seemed a little noisy, if that's the right word.
Sins and Inner Light would both display more film grain for two reasons.
A lot of Sins of the Father was shot in low light conditions so the production would have used a faster film stock because it's more light sensitive. These film stocks tend to have a much more dense grain structure.
Inner Light would display more grain simply because of the way the episode was lit. Very high contrasts tend to show off the grain structure of film (though it should be less noticeable than Sins of the Father).