For any that think the coil strength on a WOZ is an issue the fact is that coil strength can be adjusted up or down in the settings menu. I know this because I was visiting JPP recently picking up some Invisiglass and witnessed it. One can crank individual coil strength way up and if you're not careful you can break stuff! I think they may have to cap the upper levels at some point as I'm sure there are players out that want to see how far they can push it.
So not to worry, coil strength is not an issue.