From a versatility standpoint, I'd go with the Hyfire II. That's what we have and this is our 2nd heating season with it. It's in our basement and it's ducted into our regular duct work. We also had a mod done to our Coaltrol so that the Coaltrol controls our furnace fan. While we're still fine tuning things, we are overall very happy with this stove. Last year we ran it with one burner with temps down into the 20s. Once in the teens, we lit the 2nd burner. Our house was warm and our heating bill was a fraction of what it would've been using propane. This year, we had to run it with both burners even in the 20s and low 30s, but this year, the quality of our coal is not good. Even with junky coal, we used LESS coal on a daily basis running both burners than last year running one burner. We only used about 3-1/2 tons since November, and taking into account the brutally cold temps we've had, this is fantastic. We are heating 2700 sf, 1100 sf of which is our uninsulated basement (it normally ranges 58-62 down there in winter, unheated, and is now about 73). We have the Coaltrol set at 70, and it maintains 70, with an occasional 69 and up to 71. We also feel that the Hyfire II could easily heat a larger space, so there's ooomph to spare.