AAAARGGHHH! They're NOT IOPS!
A little furry kitten dies in the benchmark labs every time someone quotes IOPS on a SPEC SFS.
SPEC SFS does not measure IOPS. SANs do IOPS, and the benchmark for them is SPC-1. NFS systems do NFS operations, and SPEC SFS measures them.
Only 28% of the operations in SPEC SFS are a READ or a WRITE operation (that is, accessing the data). The other 72% of the operations are on meta data (mainly directory information).
There's a big difference. Please, think of the little kitties.