I ran through the iometer tests on the vmktree iso and below are the results from an NFS share.  The first result is with the NFS share cached which is the wrong behavior.  The second test being after the MR1 install with the cache turned off.  On the Max Throughput-50% read it is taxing the 1Gb connection now.  My numbers are not overly scientific given that there are 20 VM's running on the 3100 as I ran the test but the performance difference is substantial for those of you fighting with NFS performance. 
Has anyone done performance stats on the VNXe3100 yet?    I am doing an initial config and would like to know what kind of performance that you are seeing.   Best Regards.
IO Meter Performance Stats?