Oh i use one all the time, and leaded paste as well. Some time ago already, i modified a pizza oven by moving the heaters all on top (that way the first side components do not drop off), added insulation, a convection fan and most importantly, a sequencing kiln controller + contact thermocouple for ramp control. It works beautifully for all "regular" smd stuff, but haven't tried it for BGA yet.