OK, I gotta jump back in on this one.
Here's a detailed list of the pros and cons of my Hardy. Again, I don't want to sound like a salesman, because I'm not one, but I'm proud of and happy with my OWB.
I like the fact that it's just a square stainless shell. If it was nice and sided it would outshine all the other buildings on the farm here.
I like the grates. I shake them down every couple weeks and shovel the ashes out the bottom of the furnace into a pile I keep beside the furnace. In the summer they go to the garden. Hardy gives you a little homemade shovel for cleaning out the ash area. There isn't a pan or anything. I have a low water light on the side of the furnace facing the house so I know at a glance when to add more. That said, I barely ever have to add water. I get good burn times and it burns coal, too. It's simplly built-I don't have to rip off siding to get to the guts. There's a panel on the back that slides right out to get to the pump, aquastat, blower, etc.
It's not perfect, though. Here's some cons: There's a warning label that tells you to open the ash door first. If not it can have kind of a mini flashover effect that will take your eyebrows off. The ash drawer situation does kinda require you to hunker down on your knees to shovel it out. I don't have the light above the door for night loading that some of the others feature. I just have fiberglass sheet insulation. Maybe the spray stuff is better-I don't know.
Basically, a Hardy is a no frills furnace. Built for function, not form. If you're the kind of person with crank windows, a stick shift, and vinyl seats in your truck, this is your furnace.