according to this the most durable IMS comes with 97-00 models(double row) and the weakest at 01-05 models...

 

My 05 997 S was a launch car which worried me initially, however after talking with a few different Porsche mechanics they assured me that the issue was overblown and actually talked me out of doing the replacement. That being said I have an after market warranty and will likely replace the car when the warranty expires in 4 years. So far the car has been bullet proof (17k miles).