ok. I do have a friend though that's working with Citrix XenServer 5 and DSS and he tells me that it works fine. In fact, there're using a 10/100 iSCSI network and still getting decent performance with their virtual file servers.
There is a Forum user "jmo" who is very knowledgeable on XEN and provides some real good info. He has responded to many postings, check him out. Thanks for the info