I can agree with you there on Boo Berry, it's flavor really isn't that impressive - but at the same time, as I've also said before, I find Chocula to be just too overwhelmingly chocolatey. I like chocolate, but not when the flavor is so strong and powerful that you can't eat the stuff . . . just like I like cheese, but sometimes something can be too cheesy, such as these cracker samples I tried yesterday: didn't taste much when I first put it in my mouth, but then just before swallowing, this overwhelming cheese flavor punched you in the back of the mouth. Not pleasant. Frankenberry, as I said, I find taste like what Berry Berry Kix used to taste like (just with marshmallows added), and BB Kix was one of my very favorite cereals as a kid, though it was always so hard to find. Like I said, when I tried Fruit Brute, I found it tasted like a less flavorful version of Frankenberry - subtle, slightly sweetened.
I still think they should bring out a vanilla monster cereal with an yeti mascot, and a cinnamon flavored cereal with a zombie mascot.