KaBa Rose T90, Mona Lisa 34P, and Sullivan's Stockman 365 are cows that I know have been cloned and have offspring on the ground. As far as I know they're doing fine.
I have thougth about doing it with one cow. But it is not a cheap and if a cow is a great one she should have produced some daughters that are better than she is if she was mated correctly and flushed.
I have a cow i would like to clone and know this cow will probably die at my place when her time is up