Well before i got to X, i test drove Liberty (yep, here i admit it.. i did research first 8)).

I went with X b/c of: better leg positioning/room, better head room, steering response, safety feeling, better rear windows/positioning of rear seats - so my son could actually look around, while sits in his booster.Also i was trading in my Gr.Ch. Laredo, and i had my lovely share of issues for that brand of SUVs, so i weighted all the things and went for X.

Then again - like guys said - there was nice article on Liberty vs XTerra, that you might want to find and read.