Tank bags

Was looking to fit some sort of bag onto the GPX and have been looking at these magnetic tank bags. Are these tank bags all going to fit a GPX tank? Do they scratch the tank? Who has one?
They seem a nice idea but I keep thinking it will interfere with my reach on the handle bars.
True or untrue?
They seem a nice idea but I keep thinking it will interfere with my reach on the handle bars.
True or untrue?