I listened to the Remus sound clip and souded pretty good but I'm not sure if it would be a big enough increase in sound level for me.  If I drop several bills on a cat-back system I want to know I just did if you know what I mean.  I think the GHL is the way to go if you don't mind some in cabin resonance.  That exhaust scares little children and turns anyone's head that is within a 2 block radius at WOT.