I would think for the soy users the leaf rating would be pretty accurate. Now, I use paraffin so if it says it is strong in soy I know it will be great in paraffin. If it say it is not very strong in soy it still might have a good throw in paraffin. So, I guess that is why it is so important to do your own testing. Plus, everyones view of a strong or weak throw will vary on the person.