I always thought the alien shape-shifter was more fun than the makeup guys. I don't remember if it's the end of the third season or the beginning of the fourth, but it was Roger Daltrey who played the shape shifter (and also K Callan and Eddie Jones <g>). That covers the whole 'dissimilar body type' hangup. What if that guy had shown up as Lois in his attempt at killing Clark? Or Perry? Or what if the whole New Krypton arc had taken place a year earlier before Lois knew the truth? How would she react if a pseudo-Clark (or Superman) was using her to get to Kal-El?
It brings to mind an awesome episode from the X-Files, where the alien bounty hunter assumed Mulder's form to get Scully to tell him where the real Mulder is. When that fails, he uses Scully to lure Mulder out of hiding.
There's just something about the dissonance of having a person you know so well turn out to be someone else in disguise. For someone like Lois, who already has trust issues, that would really mess with her mind. (Then again, she seemed to get over the Superman clone's attack on her in 'Vatman' pretty fast.)
Or maybe I'm just twisted that way.
