I kind of made the move in the opposite direction -- having come back to Pentax after using Nikons for many years. I will always love (and hold on to) my Nikon FM-2n, and indeed I have asked my wife to make sure it is buried with me when I die
That said, I prefer actually *using* my Pentax equipment. The lenses seem perhaps just a little better quality than the Nikkors, and everything in the Pentax world seems to fit my hands / eye more comfortably.
That said, I would choose the PZ-1p over the LX. The seals will be in better shape, and everything else will be a bit newer on the PZ-1p. While it may be little more "plasticky" feeling than the LX, both of our PZ-1p bodies have held up quite well.