I bought Infiniti G35 6MT 2006 four months ago and gave an review three months ago. Now after driving it for 4 months I have a few things to add. Also, I came from Europe so I was biased towards German cars and really had prejudices towards Japanese cars coming to USA.
1) The drivers right hand arm rest should be higher.
2) Cup holder location is bad. Located imediatelly behind the stick a cup comes in the way when shifting gears.
3) Clutch needs to be refined since you can always hear a clunky noise when shifting from 1st to 2nd gear.
4) Seat bottoms should be longer no question.
5) I feel, sometimes, that it needs more torque at lower rpm's.
1) Acceleration is very good (better than BMW 330 MT 2006 that I tested).
3) Engine power is fantastic. It will take you out of any corner, accelerate on highway, effortlessly...
2) Braking is excellent. I feel very safe driving the car fast since the brakes are so good. It creates a lot of brake dust, but it is normal for high performance brakes.
3) Sport suspension is really really good. The car sticks to the road and takes corners really really well (I am impressed with these two "features"). I was unable to notice any difference between BMW 330 and Infiniti G35 in suspension/cornering (I am not a professional driver maybe that is the reason!?). It is also rock solid, no body roll...
4) Steering is very accurate. Infiniti/Nissan did a good job here.
5) Apart from seat bottoms front seats are quite supportive. There is a plenty of room on the back seat and in the trunk.
6) Bose sound system is excellent. Yes the car is Spartan inside. No fancy features, but I like it! It is more busines like and was built to let you enjoy the ride.
7) Ergonomics is well designed (except for cup holders and arm rest). Everything is easy to reach and Bluetooth is a nice touch.
If one wants to have a real sports sedan that matches/excels BMW 330 in many aspects, and is not ready to pay $2,500 just to have heated seats (and BMW badge in front) this is the right car.
Infiniti has stolen me from BMW although I was sure I am going to buy a BMW when needed a new car.