I talked to them when the first came out a few years go. I asked questions and they where super nice. My complaint was the "testimonials" where weak and wanted to know what the before and after oil analysis look like. I wanted to see several 25 hour oil analysis in a row without the magnets and than after, to see if there was a drop in metal in the oil. You would expect the iron would drop out right? They asked if I wanted to test it. I decided not to be a bata tester. I think they have a money back deal anyway if you are not happy. It would be great to get some real data.
They have pictures of a filter cut open with magnetic particles holding on.

Well if the magnets where not there the iron particles probably would be in the filter element, and may be some still in the oil. The implication is without the magnets the metal will travel back through the engine? Of course it will not catch the aluminum, copper or copper.
I guess it can't hurt. Many times I find aluminum or carbon (non magnetic) stuff in the filter but no chunks of iron metal. My feeling is it adds weight and cost money for questionable gain. I figure a spin on changed every 25 hours, it is good enough. However I can't think of it hurting.
It would be great if some RV'ers would do a scientific oil analysis trend study.