Car is quick for a compact sedan. Way more rear legroom than competitors and although some parts are shared between this and the Ford Focus, the Mazda interior styling outshines Corolla, Civic, Focus, Cobalt, but not Jetta. One major reason I decided on a 3 was because of engine performance. It seemed to out perform its competitors in HP at 148. One thing I've noticed about driving and do like is the quick acceleration at higher speeds (60+mph); this car really feels somewhat like a 6 cylinder at these speeds. The low speed acceleration doesn't seem that great. Everyone I know loves the interior, but here is where my complaints lie. The microfiber seats build static on your clothes and the glove compartment squeaks.
Favorite features would definitely be the interior. The inside, especially at night, is very pleasant to the eye. The gauges in the dash seem very well styled. Plastic is not cheap. The stereo is integrated with the dash which makes it look cool, but harder to put aftermarket equipment in. Seats are soft.
Glove compartment squeaks! Not THAT noticeable, but fix this. Trunk space is small, because inside of car is so big, this is why the back window extends to almost the rear of the vehicle. Improve low speed pickup. Price of 3i w/power options = 3s w/power included. Regret not getting S-model; but my "i" gets 33mpg.