Looks like the Daniel Defense lightweight upper weighs an ounce more than their upper with the regular barrel but lite handguard.
DDM4V2 upper (pencil bbl)
Complete Upper Weight: 4 lbs 3 ozs
http://www.danieldefense.com/?page=shop/detail&product_id=266

DD AR15 Lite Rail 9.5 FSP Complete Upper Reciever Group
Complete Upper Weight: 4 lbs 2 ozs
http://www.danieldefense.com/?page=shop/detail&product_id=168

I just noticed that the DD VFG weighs 3 ounces, so that would make the DD LW upper 2 ounces lighter than the DD upper with lite rail and regular barrel.