Why would anyone do that? and how close or far out to what?

The pro's know the point already, and they keep telling us about it time and time again. "Autotune" is more marketing than tuning, because all it does is try to map your VE tables, which is only the tip of the iceberg. Also the tune is about overall ride ability, not just a WOT dyno run.

There are also plenty of threads where DIY types have either tried one thing then maybe another and then maybe taken it to get a proper dyno tune. That's trial and error, not scepticism.

I think there are an awful lot of people running around on a stage 1 with a canned map of some sort ...fair enough, but don't try to say these things are magic.

Anyway, the OP was asking about canned map vs running an autotune, and there are plenty of threads about other stuff already. Maybe he'll come back and let us know how he got on.