For now, I will say it is still the best product
For now, I will say it is still an excellent product from NetApp which is able to provide full storage virtualization for storage arrays from EMC, HP, HDS, IBM, and Fujitsu, it also allow you to take advantage of NetApp storage efficiency, Integrated Data Protection, unified storage, and other capabilities without sacrificing the existing storage investment.
The advantages from V-Series:
V-Series reduces your total capacity requirement by at least 35% and typically by 50% or more using storage efficiency features such as deduplication on primary storage, thin provisioning, compression, and cloning.
Integrated Data Protection (IDP) features simplify and accelerate data protection operations. Examples include NetApp Snapshot™ copies, SnapMirror® replication, SnapVault® disk-to-disk backup, and virtualization-aware and application-aware data protection with the SnapManager® suite.
Connecting your existing storage array(s) to V-Series can provide a gateway that allows you to support all common NAS and SAN protocols including NFS, CIFS, Fibre Channel (FC), iSCSI, and Fibre Channel over Ethernet (FCoE).
V-Series controllers are able to run clustered Data ONTAP® 8, so you can include your existing storage arrays as part of a NetApp cluster for even greater functionality.
With reference to the Back to Basics: V-Series Open Storage Controllers discussion by NetApp team:
http://www.netapp.com/us/communities/tech-ontap/tot-v-series-open-storage-controllers-1211.aspx
*Disclosure: I am a real user, and this review is based on my own experience and opinions.