I have an Ibanez AF 55, the pickups are u'covered buckers, to me, the p'ups look u'finished, even though nice sounding and plenty powerful p'ups.
These plastic covers simply click into place on the p'ups, no loose or vibrating fit, they move up and down with p'up if adjusted, look nice too.
Plastic does not affect magnets, so alls good.
My fave guitar now.