This is an excellent small sedan that, while not a WRX, is still plenty of fun. The reliability and build quality have proven to be top notch so far. The interior is well-designed and sporty-feeling, and I personally LOVE the exterior design of the Impreza. Acceleration is very good from any speed, handling is very predictable, and the motor has a nice deep rumble to it. The ride quality is very good, though to compensate, there is quite a bit of body roll during aggressive cornering. Fuel economy is good for a 3000-pound car with all-wheel-drive; I've been getting around 25 mpg with hard driving, both city and highway. All in all, a great choice if you just can't afford a WRX.
The torquey and cool-sounding motor; the exterior and interior design; the precise gear shifter, and its relatively short throws; the ultra-comfortable seats and steering wheel; the pedal size and placement.
Offer some 17-inch wheels that'll fit tires wider than 205, possibly the stock STi wheels. A six-speed manual would certainly help fuel economy. A smoother transmission altogether (it can be very difficult to perform a smooth, fast shift) wouldn't hurt, either. The sound system needs work, too.