Yeah, I definitely agree. He liked her more, to be honest. I sort of think that if he had met her under different circumstances, he may have started a relationship with her rather than our Olivia. He kept reassuring Olivia, saying that it wasn't about AltLivia but it was about Olivia because he thought she was Olivia... but at the same time he doesn't realize that he's ALSO saying that these new traits that he saw and that he liked so much really belong to AltLivia and not to our Olivia. Plus there was that episode where they found that guy who could read minds and he knew that Olivia wanted to know whether Peter still had feelings for the other Olivia, and at the end of the episode he told her that he does. I can't necessarily blame Peter in this case because it does come down to preference. Yes, I think he should have realized that she wasn't our Olivia, but the fact that he liked the other one more isn't under his control. My heart goes out to our Olivia because that had to have hurt to realize that the person she loves loves another version of her more.

a love triangle "Fringe" thought not to explore.

yeah, I'm glad they didn't go that route. I hate love triangles. lol