Agree that 4 is the fulcrum. If anyone stops at 2 or 3 they are doing themselves a disservice.
I never realized that the change in tone in 5 and 6 were due to a new editor. Interesting, but it makes sense.
I think 5 and 6 were ... fine. But I have trouble pinpointing what they were really about. There is a lot of movement but no direction.