Your Tip's ECU uses fuzzy logic to determine how it will shift in D mode based on how you drive the car. If you putter around it will shift quickly into 5th gear to get the best fuel mileage. If you start driving it with a heavy foot it will adjust to go to redline for more performance. I leave mine in M all the time to keep the revs above 2K rpm as LN suggests when their IMS is installed.
There is hard data on the number and percentage of IMS failures that were reported in the class action lawsuit against Porsche over the IMS failures in model years 2000-2005. Failure rates reached as much as 10% in some of those years and the suit involved 52K vehicles and the largest number of failed IMS was in California. Model years '97-'99 had a failure rate of 0.2% and were not included probably the double row IMS had something to do with the low failure rate.
No breakdown of failure rates were categorized by transmission type, however, I've also read that Tips have a lower failure rate and fewer camshaft deviation issues than sticks but that is unsubstantiated due to lack of real data.
IMS failure does not seem to favor lower mileage vehicles over high mileage or slow drivers over fast drivers it appears, from the lawsuit data, that it is largely confined to the 2000-2005 models probably due to the shift from a dual row to a single row bearing.
