I think Idolator nails it on the head with its description of the Aussie's newest Wal-Mart single, "Rock N' Roll Train":

All I can say is that if you put "Rock N' Roll Train" on for a friend, and told him that it was actually a recently unearthed old b-side from the Australian hard-rock outfit, that person would probably believe you.

But, then again, no one ever listened to AC/DC for variety and in the consistency department, the boys deliver.