Any thoughts of putting something on the top side of the plate like Line-X or some other coating to dull the sound bounce-back?

Great upgrade.

Not really.  The engine doesn't sound louder, just a little different.  Once I got used to it I didn't notice it any more.  Call me nuts, but I really enjoy the sound of heavy rocks clunking off of it at speed.  It has a few cosmetic scratches that remind me I'm glad I invested in stout protection. 

It's been a year...and I'd buy it again.