I've used both, but wasn't aware the food service ones were all natural. They also seem to be a bigger briq than the regular orange bag ones. They're also a little more expensive at least from my experience.
Good question. I'm assuming the only benefit of having the 26" kettle over the 22" performer is the extra 4 inches? I should probably go with the Performer as the options on that outweigh the extra space of the 26 incher for me.