In simple standard case, it's just a matter of an identical twin with a different age. Can't see what's ethically questionable or complex about that.
But there's a hidden snag: normally, there would be no reason to do that. Once there is a more specific motive, the questions start popping up. Most cases have parallels already, but safe, efficient cloning would make them more accessible and likely:
Clueless idiots raising a clone to be a replacement for a lost child isn't in principle any different from clueless people today raising a normal sibling to be a replacement. But it might be more *likeley*.
Conceiving with the specific aim of transplanting is already an ethical conundrum we have to handle today, but with cloning it would be a lot more promising in fulfilling its aim, and the request much more common. Hopefully w'ed be able to grow organs without a clone by then, but you never know.