2. The Jenna Louise-Coleman Factor
One of the redeeming factors of the comparison between Peri and the 5th Doctor versus Peri and the 6th Doctor is that it made an interesting case study in how an average person would react to a close friend having traumatic brain injury. I did not mean that as insultingly as it sounds - hear me out on this one. Look at it from Peri's point of view and you'll see what I mean. She meets a nice guy who's considerate, fun to hang out with, and generally good-natured. That guy sacrifices himself to save her life and in the process is completely changed by it. He's short tempered. Unpredictable. Frequently unkind. But the only reason that he became that way
is because he saved her life. So she stays with him, makes sure he's ok. Ignores the many attacks on her person (verbal and physical) because she knows he can't help it and in some way what happened to him makes him her responsibility. That was the dynamic they never really pushed as hard as they should have back at the time. But if Matt Smith's Doctor dies saving Clara, and his regeneration comes back as unspeakably evil... How much would you be unable to look away as she Jiminy-Cricket's her way through trying to make it right? I know I wouldn't miss a second of it. And look how I got through that section without a pretentious mention of Phineas Gage? Dammit...