Given your clarification of the question... I think my minimum standard for treating X as a continuation of my personal identity (whether X is an upload, or my organic body after a stroke, or various other things that some people treat as such a continuation and other people don't) is that it experiences a significant fraction of the memories I experience, and that its other memories are consistent with those memories (that is, it's plausible that a single entity in fact had all of those remembered experiences).
That's not to say that the existence of X would satisfy me in a broader sense. Then again, my current existence isn't always satisfactory either, but I still believe it's my current existence.
In this video, long about 48:00, Eliezer talks about uploading and about how it wouldn't be murder if his meat body were anesthetized before the upload and killed without regaining consciousness.
It's arguable that it wouldn't be murder, but I'm not clear about why Eliezer would want to do it that way. I've got some guesses about why one might want to not let the meat body wake up (legal and practical complications of a double but diverging identity, the meat version feeling hopelessly envious), but I'm not sure whether either of them apply.
On the other hand, I can think of a couple of reasons for *not* eliminating the meat version-- one is that two Eliezers would presumably be better than one, though I don't have a strong intuition about the optimum number of Eliezers. The other, which I consider to be more salient, is that the meat version is a backup in case the upload isn't as good as hoped.
More generally, what would folks here consider to be good enough evidence that uploading was worth doing?