Hi arbor79
I have the smaller gassifier from natures comfort, the GT-220. I'm heating about 4500 sq ft in two different buildings and my dhw. I have one heating season on it and it is working great, it has plenty of capacity. Gassification is the way to go. It is really unbelivable how much heat you can get out of so little amount of wood, with very little smoke!. I had a couple issues with my stove and when I brought it to there attention, they sent me everything I needed to make it right, you can't ask for much more than that.
When I was looking to buy my owb I must have looked at about 10 different brands and for me it came down to the gassification stoves from Natures comfort Gt-220 and Portage & Main Optimizer 250. The GT-220 was less $ and a local company with good dealers and made in the usa (wisconsin) vs the Canadian made Portage and Main which is a very well built stove. I really don't think you could go wrong with either one of them. Good Luck and keep us posted