I've been throwing the Z Predator for about 4 months now, and I just had an ESP given to me a few weeks ago. I haven't thrown it much, but enough to compare. It's definitely grippier than the Z plastic, especailly in the rain. It seems to be just as overstable, and perhaps slightly longer, than my Z Predator, but it seems like it will beat up a lot faster. I think for headwinds and big hyzers I might start using the ESP, but stick to the Z for thumbers, forehand rollers, and most skip shots just because it'll hold up so much better.
"a man is a success if he gets up in the morning and he gets to bed at night, and in between he does what he wants to do."
-- bob dylan