Performer will be docile, streetable and mileage king.
Street Dominator will give more horsepower, yet still be very streetable. It should also return pretty good mileage.
You'll get more $$$ from the SD when you sell it, as well, so keep the Perf, even though you should brace yourself for a slew of posts saying the opposite, mainly because board members tend to like horsepower over manners.

R.