I really like my new G6. I also own a 02' Grand Am GT. I still like the Grand Am but the G6 rides smoother, handles better, has more power, is more comfortable, and just seems to have a higher level of build quality. Im a manufacturing engineer and I look for all the little mistakes people make when they bolt, weld or snap parts together - so far I can't pick out any issues on my G6. My drive to and from work just got a lot better.
The super huge four piece sun roof is great. Seats are very comfortable. There is PLENTY of room for four adults. The driver information center is very nice. The instrument panel looks really neat at night. Trunk space is BIG. The car is good on gas. The car has 4 doors but I still feel cool.
None. The car is a step forward for Pontiac. Build quality is great.