Canon "positive ion control" is making it sound fancy as they are just copying what pro-troll and Scotty have. Probably can't say black box or there get a lawsuit.
I don't believe in this theory as much anymore based on this/last years fishing since I switched. I used to but not so much now.... I do concur that some of the high liners in my area use wire, but they are out there every day on top of the fish daily. Is it the wire? I am not sold 100%, but I would like to think I would be paying more attention to the presentation to not what the DR is doing myself.
BTW most of them that know about voltage don't use boxes they crimp on anodes to manipulate the voltage as well as brushing the balls etc. That includes getting the boat checked grounded properly by someone. Wire will give you a slight edge, but a lot of fishing is technique. No voltage can replace sloppy technique.
Braid is better for me in my boat because I don't have to carry crimp, crimping gear, stops. All I use is braid with the gagnion chord as stops, and no swivels or crap anymore. To me that is the trade-off. The only thing stainless has an advantage is voltage that's it, and too me I would rather have something they easy to work with. On my boat I have a few pre-tied gagnion that can retie and up if I get a break off and running with a minute or so. I could never do that with cable.