I think he's generally done quite well - for me I like that he's willing to acknowledge when he's gotten an initial shape wrong and adjust mid game accordingly. Our substitutes from the restart have generally been doing well, as an example.
That said, I think he becomes complacent - once something works, he's inclined to stick with it instead of tailoring his approach enough to the opposition. Obviously the top sides will generally have a defined way of playing, but Chelsea aren't at that top level right now and aren't able to dictate games from start to finish.
The match that encapsulated this to a T was the 2-1 against Arsenal at the Emirates - Lampard got his shape completely wrong solely because we'd done fairly well with 3 at the back in the previous handful of matches. This was an example of him not properly thinking about how to cope with the opposition, but he then turned it around by subbing off Emerson and completely changing the shape after 30 odd minutes.