Here our breweries classify caramel malts as follows: extra dark 500+, dark 350, regular 100-180, red 40-70, pale 25, light 3-8 (this is usually some kind of carapils, rarely used if at all, as all breweries use either double decoction or stepped mash). Taste-wise I don't notice any difference between 120 and 180 EBC crystal malts.