I went with Kooks 1-3/4" LT's and a Kooks O/R H-pipe. The guy that did the install has done a tone of work on 5.0's and has found that Kooks are usually a direct fit 99% of the time. However, he has had to re-weld 02 sensor locations on ARH's before, but, never on a pair of Kooks.
My car went from 422 RWHP / 367 RWTQ with a Lethal O/R H and axle-backs to 443 RWHP / 388 RWTQ with Kooks 1-3/4" LT's and an O/R H with a revised tune.
Power and sound is there.
I vote Kooks
2014 GT - Track Pack, Leather Recaros, Electronics Package, Back-up Camera - Ported CJ Manifold, SCJ Mono-Blade TB, Custom Intake, Kooks 1-3/4" LT's, Kooks O/R H-pipe, Borla S-Types, AED Tuned - 443 RWHP / 388 RWTQ
Ordered: 3/19/2014 - Built: 5/13/2014 - Delivered: 5/19/2014