Take my information for what it's worth, this was my first and only car since the age of 19. Haven't driven other cars except for the 94 Cavalier and 92 Caprice Classic my parents had when I got my license, and rentals such as the 07 Camry.
I've driven an average of 12000km (8000 miles) for the past 12 years, and probably averaged 70-80% highway miles in that time. Winters are tough up here with lots of road salt, but only starting to see some rust now (11.6 years old with 135000km). I always drive 10-20km/h over the limit, but never accelerate above 3000rpm except occasionally when merging. I'm gentle on her, because for most of the life of the car, I was a student and wanted her to last... but love cruising on the highway.
Only been tracking the gas mileage for 4 months, because when I bought it gas was 55 cents a Litre. Getting an average of 10.5 to 10.7 L/100km or 22.5MPG with my commute (75% highway). Purely highway trips 8.5-8.7 L/100km or 27MPG. These numbers seem great when compared to EPA numbers, but seems accurate for what other drivers are getting... very good for the age of the car. Winter, much lower efficiency. Manual recommends 89 octane for the 3.5L V6, but have seen no difference with 87, which I used all summer 08 when gas peaked here at $1.50/L.
Lots of room, comfortable seats and seating position, large trunk. As a big guy, I'm comfy, friends have wanted to take my car when going on roadtrips. Seats 4 adults comfy, and no problem with a 5th adult in the back so long as one of them is "trim".
I can't really speak to performance because I am not an aggressive driver, nor hard on the vehicle, nor experienced in driving many different cars. However, nice power when merging, passing on highways and very smooth acceleration at other times. Overdrive kicks in at 80km/h and can do 1800rpm cruising at 100km/h. Handling seems fine enough, but this isn't a sporty car nor is it high-end enough to be a floaty boat like a Buick.
Since the car is getting old, I don't see many on the streets anymore, but I would highly recommend one for anyone looking for a very roomy car that is very good on gas (especially highway) for its generation. I have loved this car for over a decade now and have hesitated replacing her because it is such a big decision... been researching new cars for 2 years now. Looking at Camry, Accord and maybe Maxima depending on deals (cash buyer). All midsize sedans today are a little smaller, but better fuel efficiency.
Not considering a North American brand despite great experience with this car... just not sure what the future brings... also looking for better resale value although I plan to own 10+ years again.
Since I paid $21000 ($25000 Canadian with provincial and federal taxes) in Dec 97, if it dies tomorrow it still works out that I've paid about $175/month over the last 12 years. Not bad... got me through school and then some. They were selling new Cavaliers and Saturns for 18000-19000 without tax back then... very happy I spent a little extra.