I have a 2003 3.2S, 39k, 6-speed, that I replaced the bearing with the LN IMS bearing last weekend. I know that the original poster did not ask about the later boxsters, such as my 2003, but I wanted to point out that life is about calculated risk.
I knew about the IMS issue before I bought my first P-car, I understood that it could happen and I bought my box knowing this. After two years of ownership, my box would on occasion make a slight clunk as I pulled the clutch out, while in second gear. I decided to address the gearbox issue by installing the CMS shift arrestor. As long as the gearbox was out, I installed a new RMS (which had a slight leak), resurfaced the flywheel, installed a new clutch, and replaced the IMS bearing.
The bearing that I removed appears fine, the clutch still had some life left; however, I would rather spend my time enjoying my box than worrying about it. It drives great, brings a smile to my lucky face, and reminds me why I drive a Porsche.