I am more comfortable using OPENXML in a custom SP. But that is more because it is all I have tried.
I have not found a nice way to use DTS for this. I think that what you can do in DTS you can do with a Visual Basic program running the XMLBulkUpload object.
I have not looked at XMD and Updategrams at all.
Russel Loski, MCSD
Russel Loski, MCSE Business Intelligence, Data Platform