I don't use unfertmentable sugars as I find they leave a strange chemical taste so can't help you there. Juice and juice concentrate will result in a more appley, fruity flavors in the finished product with the main difference being that juice will dilute the ABV in the cider more than concentrate. I've also used/tried ciders backsweetened with sugar, but straight sugar, while sweet, doesn't taste like natural fruit sweetness IMO.
In all the states no door stands wider,
To ask you in to drink hard cider