[78F350]

I'm no expert, but I have been pretty busy with Boxsters over the last couple years. Since August 2014, I have owned five 1999s and a pair of '01s that all have dual row bearings.
The '99s range in mileage from 80,000 to 175,000. As far as I know only one of them has had the IMS bearing replaced and I did it because the seal was leaking. The bearing itself was still good at 129,000 miles. I got the dual row LN ceramic replacement.
One of the '01s had a failed engine at 124,000 miles with a broken rod/rod bolt. The IMS bearing still looked good, but had lost the grease. The other '01 was a parts car for the replacement engine. While I had it out, I replaced the bearing (which still looked good) with the bearing from Pelican Parts. After five years or so, I may replace it again.
Dual row bearings have failed, but lots of other parts are more likely to fail first IMO. Continue to search and read, there's lots of good info and much of the info here on the forum is experience and reality based rather than hype. If worrying about it is likely to ruin your enjoyment of the car, don't buy it, or simply have the bearing replaced.