Some people love it, some don't.....I get a slight plastic-ish twang from it initially, seemed to fade with aging, I also get that from the cap eggnog too though....I don't think I'll ever use it as a solo flavor, tons of recipes I am still trying out with other flavors to accent it though, I'm honestly debating trying other vanilla custard flavorings to see if I prefer instead, part of the joy and frustration at times is finding the best for your individual tastes
Your percentages don't look bad, least according to the recipes on ecf that I've seen, are you using it solo or in a multi-flavor mix? I tried the 7.5 vC2/ 2ddl recipe, took awhile to age, again, I think I need to try other custard for my tastes though.