I did a while back. I don't care about my heritage but I was interested in the health analysis. After some controversy, they don't offer as much in that department anymore or at least that's what I heard. The observations they afforded me weren't particularly exciting, so I'm inclined to believe "it used to be better."
Anyway, they give you the raw data, which you can use with other services, which ostensibly opens up a lot of possibilities. I kind of lost interest, but will probably look into it again some day.