Thank you, that is good information on vmfs-5.
Currently our datastores are NFS on an EMC NX4. We are also looking to add an EMC VNX5200. Perhaps we will establish new vmfs-5 nfs datastores on the new system and vmotion machines to it.
Eventually the NX4 will be repurposed for backup / archival and the new VNX5200 will be in production.