Well, if the story without the tiger is the actual story, then one's natural reaction might be to feel sorry for Pi.  If the story without the animals is what actually happened to Pi, just imagine the horrors that he went through!  He went through some horrors with the animal story too, yes, but they aren't as bad as the non-animal story.  He had to watch his own mother be brutally murdered in front of his eyes; he had to watch as cannibalism was resorted to; he was reduced to die or survive mode and was led to do things that will haunt him for the rest of his life.  He received no comfort from his lifeboat companions, was not friends with them, and suffered much, much more.  So, our reactions will probably be many:  horror, pity, sorrow, sympathy, understanding, and maybe even criticism and judgment.  You will get a lot of those reactions with the animal story too, but it was much more managable and much less inhumane, so the reactions won't be as drastic, and will be mixed with interest and fascination also.

If you find the story without the animals the better story, then your reaction could be one of self-analysis.  It probably means that you are more of a realist, more logical and factual, more scientific and grounded in what is believable and real.  You are probably more analytical, cynical and doubting of story-telling in general.  Your reaction could be one of self-discovery; you are a person who doesn't use faith to cope with life, but real, hard facts to understand the world around you.

I hope that helps with your question a bit; good luck!