No.  DNS server request overload can negatively affect NFS datastore performance.  Also, if the Isilon nodes are already busy with activity (new NFS client connects/disconnects) when the NFS datastores are initially mounted on each ESXi host, the NFS mounts will not be distributed evenly across the nodes/interfaces of the cluster.
Is it a good idea/best practice to use an Isilon SmartConnect Zone FQDN for VMware vSphere NFS datastore mounts?
Is it a good idea/best practice to use an Isilon SmartConnect Zone FQDN for 
VMware vSphere NFS datastore mounts?