I've never heard of issues beyond the needles coming out but I've never seen it first hand. IMO, no worse a record than any quality rocker that is used and abused. Some guys can break anything if they try hard enough...lol.
Harland Sharp use to use actual needle bearings, like a u-joint, but they have had caged rollers for years. I've experienced and seen some flat-spotting on the roller tips, but after a lot of use, and the only time I've seen one snapped in 1/2 is when someone clearanced the underside a lot for oversized springs. (I've found beehives work well while avoiding clearance issues.)
