i used to run 555 in front and 555dr in rear on my 06 loved them. Was always told they dislike rain, but honestly never got loose in water under light driving.
http://www.fordparts.com/Commerce/PartDetail.aspx?n=8%2bAyLzY%2b66IVnN68quKbRg%3d%3d&id=319648041&m=2&search=true&year=2015&make=Ford&model=Mustang
Mitchell system has it at 1100 also
Ive had my ruby red for 7 months now, i have 2 small chips on very front but expected in desert NM roads. Nothing of that nature on fenders, that does looks like debris damage tho.
I have the race system, when cold its loud but as it warms up it seems to quiet down.
As for the drone, if it really bothers you weld in a J-pipe, can look up helmholtz tube to see what a J-pipe is about.
TBH launch control seems to be tuned for drag radials, 3k is kinda high on stock tires i can barely keep full traction launching at 2k rpm.
So far my best results are launch with a slight bog and ease into it till 2nd.
I gotta agree that its quieter then expected for a race exhaust. drone seems to be 1900rpm under a load but isnt as bad as my past flowmasters/macs/magnaflows on my other stangs.