I think you have profited from the beneficence of some of the front desk clerks at some of the Hamptons at which you have stayed.
Have you looked at the "On-Property VIP Benefit Preferences" page when logged in to your HHonors account? The "MyWay" benefits for Diamonds at Hamptons are one bottle of water and a snack item. Per the Hilton terms and conditions, that is limit of your entitlement. Your asking for more has paid off at some properties. Otherwise, you get the "stupid" look.
It never hurts to ask but don't expect the additional bennies at every Hampton.