Seems Norfolk Southern started something when they rebuilt their SD90/43MAC's into SD70ACU's. Last I read, that program was completed and they had begun rebuilding their 80MAC's similarly. There was some mention of upgrading their motors to 5500HP.
Nothing out there sounds like the locomotives I'm familiar with, even though many of the sounds come from actual recordings of locomotives. I always attributed that to becoming used to the inside the cab sound. It's hard to replicate actual sound in HO scale. And I don't think that's the intent either.