[Giller]

How long do you plan on owning the car? Do you want every drive to start with the thought - "I hope the IMS holds out".

I personally would never change out the IMS -the value for money isn't there IMO. Instead, I drove it for a couple years then swapped it for a 987.2

But if you are keeping her for a long time, then the dollar cost averaging of the part isn't all that bad and the piece of mind might be worth it.

Ultimately - there is no right or wrong answer. Go with your gut. It's your money and your anxiety level.