OEM exhaust mod, after break-in sounds glorious IMO. I've heard quite a couple of options out there and this to me is the perfect balance. Near stock when cruising around, then when you step on it, it roars but not obnoxiously. Drone is also minimal... i'd say only when cruising on 7th gear on the highway you get a slight drone. Nothing that's going to make you hate it at all.
Just my 2 cents from having the OEM mod for about 3 months now.