Stardate 20010815.1011 (On Screen): This article discusses the fact that there are genetic differences between primates and other mammals which may mean that cloning would have a higher success rate for humans than for, say, sheep. It ignores completely that what is considered an acceptable rate of failures in sheep would be completely unacceptable in humans. If, for instance, there is a 50% failure rate in sheep (leading to 50% deformed lambs which have to be euthanized) that is probably acceptable. If there's a 2% failure rate in cloning humans, leading to monsters who have to be kept in institutions until they die naturally, that is not good enough.
It also ignores the entire moral question of whether we consider cloning humans to be evil, irrespective of the success rate. (I do.) (discussion in progress)