The main thing is that it makes it really easy to clean, therefore less likely to pick up swirls from washing. If you drag it up the hedge, no coating is going to prevent that from scratching.
Our Tig has been coated for 3 years. It was filthy when I washed it yesterday. Snow foam, then 'shave' the dirt off in straight lines with the pressure washer. It would have been clean enough for most by then, but I did a very gentle hand wash just to make sure. Still not a mark on it anywhere.