[ska]

   By the time the cooking is done, I'd bet cash money no one can tell the difference.

I suspect you'd lose that bet - informally I've tried many experiments with iodized and non-iodized salts, and the iodine can change flavor.

Besides that, one of the main reasons to use different salts is crystal size which can have significant effect (depends on what you are doing, obviously). For example, koshering salt is called that because of its use in koshering meats, where the large crystal structure helps control absorption. Likewise in "finishing" applications.