Saab cogniscenti, who do I believe?

At 60k there is no sludge. The only problem that you may run into with this transmission would be a valve-body issue. This would manifest itself as a harsh shift from Park to Drive or Reverse. If you had the transmission flushed and then several months down the road this condition happened you would probably curse the day you had the transmission flushed although the flush would have nothing to do with that. PS... you better make sure that if you have the transmission fluid changed that they are replacing it with the Saab synthetic transmission fluid. This will not be cheap....