Interesting post, Josh, and thanks for it. Thanks also for flue length and ash pan info. I suppose rear exit versus top flue vent followed by pipe straight out through the roof could also be a factor in preventing cat clog, since it adds a 90 degree. It may be that when all five factors are present (no ash pan, top vent, long run, internal chimney, and cold climate), you are likely to have a cat clogging problem. Easy to add a damper, easy to add an ash pan. Pain to change the venting since it moves the stove out into the room, and changes all aspects of the room as a consequence. Cold climate, nothing you can do about it. Internal chimney, nothing you are going to do about it. It is interesting how some have such an issue with smoke smell, while others don't. Wonder why that is? And at least one person has both problems, so strong draft definitely doesn't stop the smoke problem. Would really like to figure out WHY some are experiencing it, and not others. I will get a very minor smoke smell from time to time, mostly when the cat is clogged but engaged. I figure then the smoke is just finding the path of least resistance out of the stove, so any small opening (like the roll pin hole) could allow some smoke emission. My smoke smell does not occur often enough, nor is it severe enough, to cause me to try to resolve it. It's not as bad as an open fireplace by a long shot. Just occasionally enough to make me aware there is a fire burning in the house. Smoke alarms and CO monitor have never registered any problem. I checked my door gasket recently (original issue, early stove), and I can't get a dollar bill out when I close it in the door, so I'm definitely not leaking smoke there. My original gasket has been perfect so far. I've never noticed any build up by the top back of the door. I believe you mean of creosote inside the stove? (Though that is near the area where I see the fire burn brightly early on ---upper right rear. Lately have been believing that is caused by the roll pin hole.) Next time stove is cold I'll have to shine a flashlight and look through the window. A bit hard to see there.