actually grey or local set after warrenty is all the same already, still must pay for cleaning services.
a local set still can bring directly to service centre while a grey set need to bring back to the shop where the cam is bought.chances are the they will bring to a third party shop to fix whatever problems the cam have within that 1 year shop warrenty.
grey sets are only slightly cheaper if they are bought in from japan so no point might as well go for a local set.the only good thing is their kit lens carry international warrenty but their body only has warrenty from japan where they are purchased from.