Once I've completed that, I'll send an email to you.

Once I complete that, I'll send an email to you.

Both seem ok to me; however, I'd go with "Once I've completed that". please advise.

Could anyone please explain me the nuances of the comparison made above ?

Full Member384
Nuances fail to strike me. Perhaps the first suggests that he is more actively working toward completion, but perhaps not.
Veteran Member114,202
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