If the map has your address off by a block or so, it's still easy to get your exact location for "Home" recorded... you just need to be parked at your "Home" spot to do it.
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On the whole, we don't recommend that you specify your exact home location in any case for security reasons. If your GPS is stolen from your vehicle while you're not at home... well, you get the idea. Nothing wrong with having Home point to the closest major intersection or something.