I've made both. I have never, ever had any problems with any recipe in that book. The cakes are really easy. She uses the reverse creaming method a lot. The frostings/buttercreams are not that good for what we use these cakes for, because she uses a lot of heavy cream-based buttercreams. They're delicious, but you know you have to refrigerate those cakes and serve them about the same day. I have taken the flavor ingredients out of those cream frostings and incorporate into my IMBC.
In 2008 (I think) there was a group on the Internet called The Daring Bakers. They baked for a year through the book, choosing one recipe per week. Most of the cakes were a success with them.
I have made the vanilla buttermilk every time I need a vanilla cake, and the other one about 3 times. They are about the same thing, I think. There's actually another vanilla cake at the end of that book that it's "for weddings." If you compare the recipes, they're the same thing with a slight difference (eggs mixed with the vanilla, I think).
Cake was used in this project, for a wedding:
http://smittenkitchen.com/2008/07/project-wedding-cake-the-cake-is-baked/
I read every comment before I bought the book, but that's because I have an obsessive behavior. lol