With how soon that exhaust made it to market hopefully that will mean soon enough we will see headers come to market. If there's any way to improve how the stinger sounds it will be through a headers back system. Won't be cheap but already the 3.3t Stinger sounds great, now we just need to open it up even more!
The stock exhaust sounds fine to me, at least from what I can hear in the few reviews out there. Not exactly a throaty sound, but you'll definitely hear it coming down the street when accelerating and it has a proper sporty sound. Though I wouldn't say no to a comparison video once your Stinger arrives.