With 11, I feel like the energy and enthusiasm is completely authentic. Is it just me who imagines Matt's Doctor would be EXCITED by regeneration rather than dreading it?
Never thought of that, but now that I do, it feels exactly right.
And you're not alone, guys. It took me ages to get into Who, because it was so uneven. I watched a couple of S1 episodes, then a few months later (after prodding from several friends), I got into it, until the finale. Then the first couple of S2 episodes, and then I stopped again...
I could see that both Tennant and Eccleston had a great grip on the character, and the show could hit high notes when it wanted to. But when it didn't, it stunk. Badly. And as you have said, the 2 part of the two parters always disappointed. RTD set the stakes quite brilliantly in the first parts, I give him that. But never solved them right.
That's why I like Season 5, overall, more than the other seasons. And it's the season I would use to introduce people to Who. I would tell them, once they've watched 5, to watch the first seasons, now that they've got a handle on the show and the character.