I don't know how you qualify "hit the worst" in this case. Gwen was a one dimensional character before the change and after the change. SAME as Harry Osborn. SAME as Flash. The same would probably have happened to MJ had she actually been a real character under Ditko and not a running gag of a mysterious character with a flower covering her face
And Peter Parker softened so much that he was practically a different character, and considering he was a main character and received the bulk of the characterization before this, that was tough to swallow. Not that it was a necessarily bad thing though. I thought the softening of the characters was one of the best things to happen to the book during this era. Peter's continued isolation was pretty depressing at times, and got a bit repetitive and old, and the fact that he now had a group of friends was a very good thing, and his supporting cast was never stronger than during this era.