To start, I bought the car with a few known issues, all of which were covered under Mazda's 3 year/36k mile warranty. Issues were:
Shifter bushings worn (common issue).
Driver's top latch not sealing properly (broken nipple guide).
Dealer fixed problems without giving me too much hassle. The only real issue was that since the shifter sits right on top of the transmission, the faulty bushings and broken ball created a gap for fluid to leak out, run down the transmission, and onto the catalytic converter causing a burning smell. I got the dealer to replace the transmission-driveshaft seal as well, just to be safe, and since then, the smell has disappeared.
I have not had the car long enough to experience any real issues otherwise.
Let me start by saying that I work for a used car dealer from who I purchased the car. Out of all of the Honda S2000s, Porsche Carreras, Audi S4s, and BMW Z4s I have driven on the job, no car really excited me as much as this little Miata has.
I believe this car is the perfect roadster, and many critics agree. It has everything you got in the original Miata, but since the engine is now turbocharged, the complaint of lack of power has gone away.
Steering is very precise and offers great feedback, and just the right feel and resistance.
Seating position is very good, although since I am 5'11" I would have liked to sit a little lower, but I never have any visibility or comfort issues. Some bigger/stiffer bolsters would have been a great choice for this Mazdaspeed, but the stock seats are great as well.
Power is good, combined with the short gearing, it really makes great use of the engine. The only downside is that at 60mph in 6th gear I am at 3000RPM, 80 at 4000RPM, 100 at 5000RPM, and since redline is only 6500RPM, the car would run out of gearing at ~130mph, but that's not what this car is about.
Handling is near top of the line. Upgraded OEM Bilstein shocks really make a difference, producing less body roll and sharper response than the regular Miatas. The stock Toyo Proxes 4 tires are nothing to brag about, but even with them, this car can pass just about anything on the outside of a corner.
Shifting action is great. Clutch travel is short and pedal offers great resistance, and the shifter is short and precise with just the right amount of gating.
Brakes are responsive and strong, even with my somewhat worn pads.
Throttle is very responsive, although I could have asked for more resistance in the pedal.
Fuel economy is good when you take into consideration that it's a turbocharged sports car; I generally get 22mpg city with spirited driving on occasions.
I have upgraded this car with an intake kit from FlyinMiata, which upped the power pretty significantly, and turbo spool is now much louder, and seems a bit smoother.
Stereo system is great, BOSE 6 speaker with a 6disk in-dash changer are great for longer trips.
I love this car!!