Amish Friendship Bread vs Sourdough starters

Hi,

I make sourdough starter one of two ways: water and flour in a jar, feeding it everyday for about a week or flour, water, and a pinch of yeast and feeding it for the week. 

I'm interested in Amish Friendship Bread and looking online I've seen several different versions all of which use a full packet of yeast from the start. Since the starter is kept for years and years, I'm wondering what the flavor is like when compared to a usual sourdough starter. 

Does anyone here have any experience with AFB? Any thoughts on the results?