I thought I would share my experiences with my new Opel III stove which I just began using in our newly-built house for the first winter. This stove has always heated very well, but I was never really satisfied as my burn times were unreasonably short. I finally determined that this was caused by a leaky seal caused by a very poorly-designed single door - the hinge is non-adjustable. This is a major oversight from a manufacturer who should really know better. I contacted RSF about this, they informed me that they have upgraded the rope seal from its original 5/8" size to 3/4" and that this effectively solves the problem. I was sent a new 3/4" seal free of charge, but after installation the door still had two spots near the hinge side that would not pass the paper test. I then purchased another length of 3/4" rope seal and glued it to the door, this time scrunching the seal up in the problem areas. The door now seals perfectly and I am now amazed at how well this stove performs. I have full control of the fire and can easily achieve an overnight burn. I know that this is not likely a long-term durable solution to the door-seal problem, so I am thinking of making up a bump bezel that I can screw onto the face of the stove that will press into the rope seal when the door is closed - many stove manufacturers have such a bump designed into their stoves to create a more effective seal. I am now extremely happy with this stove and can see that they have really designed it to burn well, they just dropped the ball when they stuck on the single door. (Opel II's had double doors with adjustable hinges) I know the bi-metal air-control unit is unpopular with some, but I personally believe it is a beautiful thing as it really does help to produce a more consistent burn and makes it impossible to over-fire the stove. I can load this stove right up and run it wide open, the flue temperature will top out at around 600-650F. (measured with a probe in flue) Bottom line - the Opel III is a great stove but only for those who can tinker!