I love my OWB, just like anything else it requires maint. pumps, fans, water treatement. I like not having the mess from bringing the wood inside. I keep 4k sq feet at 73 no matter what the temperature is outside. Better like to cut wood because an OWB definately will eat it. I will burn from 8-12 full cords a winter depending on the length and harshness of the winter. Most people don't realize I have one since it's 150 feet from my house. Heating my water is also a nice plus especially now that I have two girls that enjoy long hot showers.
Any specific advice your seeking? I've burnt wood inside, and now outside and I wouldn't go back to burning inside. Burning w/ a Woodmaster 5500, I think there are several brands that are just as good if not better. Most important part of the install in my eyes is in the quality of the PEX pipe and how well insulated it is, this is one place I wouldn't go cheap.