The WRX should be better in fuel economy but doubltful at 20-30% city. These are higher performance sedans being the key. People should know there's a penalty to be paid when owning such a car. Not to mention, they can only charge so much for the car so something has to give. There is always the regular anemic NA model that gets significantly better fuel economy using 87 gas.
Moving anything from a stop with AWD will be taxing to the fuel economy, unless it's a hybrid, I can't see it that much better than 22-23mpg at the most. What I do expect is considerably better highway numbers.