I agree. I don't see how even an FAI could reproduce a model of your brain that is significantly more accurate than a slightly modified standard median mind. Heck, even if an FAI had some parts of your brain preserved and some of your writings (e.g. email) I'm not sure it could reproduce the rest of you with accuracy.
I think this is one of those domains where structural uncertainty plays a large part. If you're talking about a Bayesian superintelligence operating at the physical limits of computation... I'd feel rather uneasy making speculations as to what limits it could possibly have. In a Tegmark ensemble universe, you get possibilities like 'hacking out of the matrix' or acausal trade or similarly AGI meta-golden rule cooperative optimization, and that's some seriously powerful stuff.
Giulio Prisco made a blog post giving permission to use the data in his Gmail account to reconstruct an uploaded copy of him.
Ben Goertzel copied the post and gave the same permission on his own blog. I made some substantial changes, such as adding a caveat to exclude the possibility of torture worlds (unlikely I know, but can't hurt), and likewise gave permission in my blog. Anders Sandberg comments on the thing.