Test drove one on the weekend...
Power:
It is one heavy car. Power is definately there. With TCS on, boost is limited in 1st and 2nd gear, so if you floor it you won't spin the tires. But it is quick to 100km/hr and even pulls above that easily.
3rd, 4th, 5th, and 6th still all pulled strongly all through the rev range. There is no signs of boost lag, but then there is no loud BOV sound either.
They switched from a FMIC to a top mount, so the hood has more of a bulge upwards, making it harder to see the nose of your car, it is a lot quieter and refined than before.
Exterior:
Styling... its still a mazda3, with small distinctions that you are getting something special. The hood has a power bulge for air intake and plastic trim pieces that funnel air to the top mount IC. The spoiler is bigger and more pronounced, and the 18" rims and 225 rubber fill in the wheel gap.
Handling:
The car definately was heavier than a dsm, and not as light and nimble than a Cooper S, but for a 4door, it was ok. Powering it off a turn, the lsd really helped reduce understeer. The chasis still had the sedan feel, but was stiffer than a regular mazda speed 3.
Steering response felt heavier than a regular mazda3, and it maybe just the beefy 18" tires, but i felt it was lacking in road feedback. And the steering was just heavy to compensate the lack of feeling.
Braking:
Braking was impressive... the car has a stabilizer controller that distributes braking power to the rotors that needs it... end result is the car doesnt nose dive as much and is much more stabilized in extreme braking.
Interior:
Aside from the sport seats that were designed for the bigger north american that don't really hug the smaller framed guy, there isn't much more difference from a regular mazda3.
The speedo went up to 260km/hr instead of the 220km/hr. The rev counter was the same, as well as the gas,temp, and other sensors. There was no factory boost gauge or egt.
The center console was a little different, more digitized, some more functions for climate control, but really its the same.
Audio was bose, and was ok for stock, 6 speakers with a tiny sub.
You get an additional 2 more airbags, totally 6 airbags for safety, and they fixed the annoying security feature that allowed theives to punch yer door and unlock yer car.
Other than that, the inside trim was the same.
Conclusion:
260hp is a lot of power to put down on a FWD car, but over all I think it can be a fun daily driver if you don't care about your 0-60ft times.
Only thing is the engine bay has a lot of plastic... modding it will be very annoying, and there isn't much room to add stuff...