We had one as a rental when we flew to LA in 1999. Broke down on us twice. First time was wacky speedo and tach, they took it in and fixed it. Second time we smelled coolant, looked over at the temp gauge and it was pegged, blew the head gaskets. I agree with Wren, they were by far the worst mistake GM ever made.
I posted some questions about the Catera on here a while back. My grandfather has a 2000 Catera and it has any number of problems. On the plus side, with the optional vogue-type tires and sport package it is nice of the back roads. On the downside, its hard to drive a car thats always parked on the service drive of the Cadillac dealership.