I keep seeing newer Maximas around town and think, "That's a nice looking car", realizing now that it looks quite a bit like the GS, which is why I like it. I think Nissan is trying to emulate the GS, but if you've driven the GS, you know there is little comparison.
I purchased a 99 GS300 w/60k about a month ago and it is amazing. I have driven quite a few japanese sports cars and nothing hold the road, has the ride or handles like this vehicle. The variable valve timing spreads the torque out across the powerband and the electronic transmission is AMAZINGLY responsive.
I've had this car in snow and ice here in Topeka already, and a lot of it. The car has excellent traction for rear wheel drive. Remember however, that traction is extremely dependent on the tires you run. My rear-wheel-drive GS3 with good Michelin tires does better than the front-wheel-drive Civic I had that had poor tires.
As for service costs, at 60k, the manual calls for new plugs and to replace engine coolant and brake fluid. The timing belt is not called for until 90k. At 60k, my GS3 has clear brake fluid and engine coolant so I'm not going to touch that. I may try to replace the spark plugs myself. The manual calls for special dual-tip plugs for this vehicle so make sure to use the right plugs. When a GS3 hits 90k you can have the timing belt replaced by a reputable garage and it'll cost half what the Lexus service would charge.
My gas mileage is an honest 20mpg around town. I have yet to make a road trip however so I don't have the highway mpg.
I've known a few people with Lexus cars and they have over 150k on them and they still look and drive like they are a year old. AND they still have an impressive resale value.
One more thing, if your thinking of buying the Lexus GS, drive it and you'll never want to sit in a Maxima again. The Maxima is a great car but the Lexus GS is on a whole higher level.
Unfortunately I'm going to have to sell mine this spring to free up some cash (I'm going to get married) but I'll be spoiled by Lexus until I can pick up another one in a few years.
Peace on, Lexus drivers! B)