I have had, and enjoyed, many bars with chocolate combined with ginger, but most of them do not have ginger oil (rather, they mostly have candied ginger). The cacao content of this bar from the Italian chocolatier Aiello is at 53%, and the ingredient listing looks good, cocoa mass, sugar, cocoa butter, soya lecithin, vanilla and ginger oil.
How does it taste? The chocolate itself is pleasant, a good eating chocolate. The ginger flavour is interesting, it's throughout the chocolate, rather than in small pockets surrounded by chocolate, and the ginger is not overpowering or hot (something I like with most ginger dishes, but I would say it's not something that I would think would appear in a chocolate bar, it may have limited appeal). This is a bar I would choose again to eat. The bar cost about $3 on sale.