yes to both, but the loss in performance is quite simply due to the contact patch being thinner than before. it makes installation MUCH easier but you've got to trade something.
that being said, the performance will pretty much whip anything else out there anyway, so it's really not that big of a deal.
the install goes the same way, remove the bucking mound and file/sandpaper the patch to fit. the z-kit simply removes quite a lot of the fussing about with the barrel window and patch.
too busy tinkering to play.