I've had so many discussions about the difficulty and really, Chris' isn't harder, it's just less fun. Fewer inventory slots, fewer guns, more restricted path with keys. It's just a much more linear and rail roaded game, sure he moves a little faster and has more health, but that's a lame bonus.
Big fan. Been catching up recently and only have one episode of Smith left. And yeah, Tennant is best doctor, but the way I usually break it up is that while he's the better doctor, Smith has way more legitimately great episodes, as where Tennant is a lot more cheesy sci-fi, which is what I personally want.