IMS replaced with roller bearing?

[Finnegan]

I'm looking at a 2004 and the current owner had the IMS replaced with a roller bearing, not the LN retrofit. The guy at the shop who installed it says this is a better solution than the LN.

Without igniting past wars here, can someone give me a primer on roller bearings, and whether or not this is a good solution to the IMS issue?

Thanks!