THe best thing to use with magnets is Traveller's TargoMag. Turns the zone into a cross hairs. It's so much simpler to work with. And Keith has got it right. The base does count towards deformation. Having worked with them for years Id have to say magnets are bloody brilliant. I routinely convert clothing over from one figure to another using just magnets. Commercial quality conversions. Don't go out and buy a magnet set (at least not yet unless you need it specifically for something). Get in there and use them. The best way to learn about something is to get in there and use it. Then, if you either can't learn them, or want to learn more, or want more power, go look around at the magnet sets available and see if you can find what suits your needs.