Based on the aerotest vids the one guy on here has done, I think I'd be a little worried about the tow strap flapping and fluttering around back there in the dirty air flow. It likely won't take too long for it to beat the paint off your bumper.
Outside of that, aesthetically I prefer the dual exhaust (it's funny that so many want to switch their single to dual on other cars and yet some want to switch a dual to single), but as long as you're happy with it.
Good to see GLaDOS is keeping occupied.
