Currently, <30 seconds on PS3. That's not including time for lightmap baking etc. for environments. Character assets and single models/props are nearly instant.
Forgot to include the refs/inspiration I've collected =_=! gah! They aren't from any specific source. They were simply googled and no infringement intended...
On a side note, the Fabric Engine 2 is launching at Siggraph, this includes Modo integration alongside that of UE4, Maya and XSI. https://vimeo.com/135353349