I had an issue last week with my ESX4 environment. In attempting to cleanup my data-stores and backing up files off my Dell/EMC AX-4, I ran into a slowness issue migrating files off the Sans via the data-browser tool within the VI client.
I tried WinSCP but ran into some throttling capping at around 5-6mb/s. My files totaled around 110GB from one of the stores.
I did some Google searching and found this tool from Veeam.
http://www.veeam.com/vmware-esxi-fastscp.html
It claims to be 6x faster, but I only saw improvements from my 6mb/s to 12mb/.
