I have a '99 GLS with the 3.5L V6. It handles well, and jumps from 55 to 85 very (too) easily. My biggest complaint is quality of the components. I've had nagging minor problems (door trim, uneven fit in interior), more serious mechanical defects (warping brake rotors, crank shaft sensor), and major mechanical breakdowns (power steering went out, rack replaced 3 times). Without those issues, I'd love the car.
Overall styling, acceleration at highway speeds, handling
Since it's going away, this is a moot point. If looking to buy a used Intrigue, probably best to look at later models, or plan on making a significant investment in repairs.