Hitzer Model 82 F.A.

Does anyone know much about these stoves. The searches I tried didn't turn up much information. I have basic information from hitzer, but nothing else. I like the style of stove and that it can be turned into a furnace if I want to with the forced air kit. Something I noticed in the literature I got is the F.A model of the 82 it will burn wood, but the U.L. version it doesnt have it listed to burn wood. I think this probably has to do with emissions and filters. Just a side note the basic U.L. model is a little over $1000 while the full F.A. furnace model is almost 2,000 with options in the middle. My questions are how long do they burn on a load of coal, how much do they hold, is the "down draft" design considered good or bad? and other general obervations, and size of coal to use.