As Monnat Systems said, since you have premium support, you currently get advance replacement of hardware. Without premium support, you'll be back to the default hardware warranty, which requires you to send in the defective hardware before replacement hardware is available.
Furthermore, as of Firmware 9.9, ZD's enforce that software updates require an active support entitlement. Your ZoneDirectors will no longer allow you to apply new software updates if they do not have a support entitlement.
Less importantly, you'll lose access to some support KB documents (most of the documents that pertain to ZoneDirectors), as many of the support documents are Premium only.
