Joe,
I just saw your comments after I have written my post. I think the cases bcp or sybmigrate faster is rare and you need to work on it a lot to make that option faster. Sybmigrate may do the job faster if you can utilize enough number of engines in parallel. But, you need to test your configuration. Also by using sybmigrate, you can exclude big indexes during migration and create them afterwards so that you can change the server configuration between each index creation. However, it requires a lot of scripting and testing.