I've seen both in person and don't REALLY know for sure, but I'd assume that doing real wood in the MMIF woudn't work as well, since to get the fire hot enough for good smoke, I'd think it would really ramp up the temp in the cook chamber.
Again....not speaking from any experience.
I've looked into both versions of the Meat Monster and they're dang fine cookers for sure.
18.5", 22.5" OTS
Large BGE (chambersuac's)
The Fiery Furnace (chambersuac's)
Big JT's Smokin' BBQ Competition Team