A 24 year old vehicle will be exactly as good or as bad as the last 24 years of maintenance and repairs. Any known issues, pattern failures, or common problems will probably have been ironed out or updated by now. My wife had a 2001 Sable bought in 2001, she drove the car for 15 years with no major issues outside of warranty (it did get a new torque converter under warranty) and then I drove it for 2 years before selling it to a college kid. It was a great car.
My wife’s (and later my) 01 Sable had the 3.0 DOHC and I would take that engine over the Vulcan any day. Having said that, the Vulcan is a durable, reliable workhorse, but underwhelming in performance.