Now that I've had the new Saab 9-5 wagon for a couple of weeks, its given me a chance to compare the L-series to the Saab in how it drives. The L-series is very definitely a stable car in the handling department. Its limits aren't as high as the Saab, but its still very good IMO.
The one weakness is the steering. When on-centre I find it a little vague and it would be nice if Saturn had made it a little quicker. In the corners the steering is fine, I get a good sense of where the wheels are pointed. My LW300 is still a fun ride. Its not as much fun as the Saab, but you'd expect that given the big difference in price. The Saturn since its non-turbo has better throttle response than the Saab. Maximum torque is available immediately, which is great around town when you need it.
The L-series also has no problem at all pulling our utility trailer, which we use when we go camping in the summer. The V6 has plenty of grunt at any speed under about 70 mph. I won't drive any faster than that when pulling the trailer. I've never tried the car on a flat and straight stretch of road to see how fast it can go but it certainly will go as fast as I need it to. Going too fast would be irresponsible, I'd have to take it to a test track or something, but it might look a little silly seeing a wagon blasting around a race track :)
They used to say about the old VW Beetle that it wasn't a speed demon but it would go as fast as anyone needed it ( highway speeds). In Rockford there is a track called Rockford Speedway where they've had old school busses blasting around the track so I don't think it would look too funny to see a station wagon.
I guess wagons aren't that bad on a race track, I seem to recall Volvo used to race them against smaller cars. The weight distribution must be pretty good which would make for fast corners.....