The 7970GE overall looks to be the fastest single GPU card available. 
http://www.anandtech.com/bench/Product/618?vs=555
So it is in the position of being where the 480 was two years ago.  Fastest card on the market and loud.  I doubt it is louder than the 480 furnace jet engine, but not having owned and used one, I can't give a comment on what it sounds like 
 
I'd take the 7850 over a dustbuster 470 any day.  Faster card, more OC headroom, better thermals, better acoustics.  Just plain better.  Not sure how many people are looking to buy cheap second hand cards rather than brand new 28nm tech.  So that is a wasteful discussion regardless.
I'm sure if someone wanted older, loud and second hand parts, they would just get a 480 rather than a 470 anyway.  I'd bet you can get second hand 480s for $100 if not less, who'd want those obnoxious crappy cards in 2012 ?