I just made my first keg of cider from supermarket juice for the missus. Its bl**dy unreal, so easy in comparison to AG brewing.
Its very concentrated so you don't end up watering down your ciders alc content as much. Of course this is only good for kegging and needs to be kept cold to discourage further fermentation. We did some taste tests with varying amounts of the concentrate until it reached her liking and then scaled it up. Turns out almost exactly 2 x jars of concentrate into the keg is to her liking (medium sweet, still a slight dryness lingers). Concentrate is not super cheap, but it does taste as good as any quality bottled cider I reckon.