I average 21 MPG with a pretty even mix of stop and go city rush hour driving and 65-75 MPH highway driving. One thing I notice is the AC seems to have no effect on mileage.
Would good or bad mileage affect my satisfaction with the car? You bet, I love this car buy I also don't like being dependent on other nations for fuel. Of course one has to answer how bad does the mileage have to be, to be considered bad.