There is something to be said for maintaining a mid or upper tier status in at least two hotel programs, presuming your travel schedule would permit such a dilution of your stays. The geographical distribution of Starwood and Hilton properties is not homogenous, so you would almost certainly encounter some locales with better coverage by one chain or the other. Of course, the perks, amenities and compliance proffered by each of the disparate properties is not homogenous either.

Rather than exhaust a one time comp to an upper level tier by Hilton, Gold membership should be extraordinarily easy to acquire these days and would afford you most of the perks enjoyed by Diamond status. As has been recently discussed on this forum, at properties like the NY Hilton, Diamond status tends to mean very little at all. And, for what its worth, they are a compliant property. If you do eventually wind up jumping ship, it might still behoove you to "try before you buy" rather than simply quitting Starwood cold turkey.