Most Helpful Member
It's only 'spot on' if you're lucky, it takes no account of the local conditions - how could it?.Actually it is spot on. You tell it your home address so its not so "vague" and when I google map the stations you can see the towers.
Essentially it's just a theoretical suggestion based on distance from transmitters (and their power of course) and the underlying geography.
Basically if you're in a good area and it's already obvious what mast and aerial you need to get good reception, then they are correct - but if you're in a troublesome area (particularly where it varies completely from house to house), then they are utterly useless. The ONLY way is to have local experience and professional knowledge.