I should probably do the same. The few times I tried the stovetop method, there was definitely an art to it..
I have gotten pretty good at it. Just as with the heatgun/dogbowl, the key for me is gradual ramping up of the heat for the first several minutes, and constant movement of the beans so that they do not scorch. In the stockpot, I am constant whisking the beans around, in the dogbowl, I am using the muzzle and airflow of the heatgun to constantly move the beans around.
I have one of the first Behmors made, back in 2007, and I think it is not heating up as much as it did when new. I used to be able to roast a full pound to full city in about 14-15 minutes, and now it takes about 20. I have decreased my batch size to about 14 ounces to maintain adequate roasting times.