The NAS connects to the same Gigabit switch and operates fine.
The ML350 (ESXI) shows 1000Mb connection under networking in vSphere, so I don't know what the hangup is.
It is certainly behaving like a 100Mb connection.
I also have a VM-only network, and I tried transferring the same ~700MB file over that network. (from a Win 7 VM to Win XP VM) That took 60 seconds and it should have flew considering its not actually going out on the communication media.