Grey Market Items.
I have never bought grey market based on warranty and who would do the warranty work. If I read this right the maximum warranty period is one year. If you are buying, for example, a Tamron lens whch typically comes with a 6 year warranty you really have to weiigh out the cost advantage vs. the longer warranty period offered by Tamron. Unless the savings was pretty decent it would seem you would be better off buying the USA product.
The other question on a grey market item is just who does the warranty work for B&H and Adorama? I have bought from both and both are good, ethical companies to do businesss with. However, would the source they would use for warranty work be equal to a factory warrnaty source?