IMS replaced with roller bearing?

[Perfectlap]

Assuming you're ditching the factory bearing and are replacing it with the LN, the roller bearing Kinda fixes a non-existent problem imho. The likelihood of failure during the LN's intended mileage, is very slim.
Let's say for the sake of argument the roller bearing is x% more effective than the ball bearing, you're already in rarefied air to begin with. Do you really need that extra x% if it comes with some unknown variables (largely because so few roller bearings have seen high mileage) that are unique to the roller bearing approach?

Either way, the point is to get rid of the factory bearing. All bearings, whether roller or ball bearing have a lifespan in this particular application. if you're still on the original, don't know the exact history of your car's servicing, and have a single row, you should get your head examined.