Personally, I don't dislike replaceable events, they seem a fairly logical transposition of "revisions".
I suppose replaceable events are less fragile than a diff chain; all it takes is one missing event in a chain and the update is aborted, or am I missing something?
Instead with replaceable events we can loose old updates (casual or by relay pruning) and still have the final version.
However my perspective for now is too theoretical, I need to deal with more edge cases.