By 'magnetic' do you mean electrostatic spraying? That method is nice but it too has a fairly high price tag for the equipment. Not to mention that improper use can cause nice long sparks in an environment loaded with volatile organic compounds. (This is not to keep anyone from using electrostatic spraying - just make sure to follow directions.)
But that the method can reduce, not eliminate, a good deal of overspray. Another minus is that internal corners may not get enough coverage, but a big plus is that outside corners will (Faraday effect).
So by all means, if the work volume will pay for it, that is another altrnative.
CG