Zombie thread, but I do love Luxardo cherries. Never occurred to me to use them in a beer. They have a deep, concentrated flavor and aren't as sweet as maraschinos which might make them perfect for a rich stout. They are packed in Marascas liqueur which gives them their signature flavor, I'd dump the whole jar into an RIS, I would imagine they compliment the smooth espresso/chocolate flavors of Carafa III quite well.