Bought it new in 2009 and I was in love with it. 1200 miles later, my turbo start failing during acceleration. Take it in, I'm told Mazda knows about it but there's no fix. Take it in a second time, they basically ignore me. There are tons of rattles and squeaks that start to develop, though most will go away if you squirt some WD40 on it or shove some foam somewhere to create pressure to stop the rattling (like the steering column).
It's still a fun car and definitely worth the money. There are some things that I do love about it, but I'm going to move on since this car isn't exactly great for stop and go traffic that I'm typically stuck in. (Didn't have a commute when I bought it.)
Turbo (when it works), exhaust tune, steering and handling, responsive brakes, easy gearing and shifting, excellent feel in sharp corners (just be sure to turn off the traction control or it gets weird), fairly decent gas mileage.
Forgiving engine in the odd times you don't pay attention to what gear you're in starting from a dead stop. I've probably only stalled half a dozen times in the two years I've had it. The transmission is smooth (though rare times it feels like the gears aren't quite synced but remedies itself by the next start of the engine).
Have an intermittent wiper mode. There's the auto-wipers but living in Seattle, I don't need my windshield wipers to go superhyperomgsofast when it's only misting outside. I hate not being able to control the speed. And if you leave them in auto mode and ice developed on your windshield overnight? Say goodbye to those wiper blades as they glaze over your windshield.
Also something to reduce the torque when there's snow and ice would be nice. Or move power to the wheel that's gripping or something. Even with studless snow tires, I've lost traction way too many times doing almost nothing.
And uh, fix the turbo issue?