yea the def system does not kill engine its the egr that does, the def system is just costly to repair
euro cabovers have flat floors so you can stand up in them, they just dont have the overall space a conventional does
that was the case with the old ones. the argosy had the room to stand up and the euro cab overs do aswell and they usually run full cab and air suspension, unlike us trucks that dont run full bags on the cab