Here is what I have experienced with smoke: When operated improperly and impatiently, yes - you will get significant smoke within the firebox. I have not had any smoke leak out of the unit - but I have had some pretty dark moments inside the box. When operated properly, the stove works great. The video on the top down fire is a good source for how to operate properly. Also, I find building a small hot fire and continuing to build up from there works every time. I admit, sometimes I get a little lazy and throw on a log that is just too big for the coals and fire that I have built up. The "too big" log will smolder, billow dark angry smoke, then eventually catch on and burn. Sometimes to accelerate the process, I will crack open the door a tad and create swirling drafts until "too big" has burned to my satisfaction. Now, I am not saying that the other person is operating incorrectly - BUT, I do find in my own operation that significant smoke is a result of improper ... or rather impatient...use.