I think it's horsecrap especially the part about higher HP per liter blah blah...
With turbo's you're pretty much throwing the displacement argument out the door as you talking about an "un-natural" way of processing large volume of air in a combustion chamber... There are plenty of diesel motors in europe with turbo's that will whoop this motor's ass especially in commercial trucks. In regards to sequential turbo's, don't see what so special about that.. the concepts been around for years..