I use a 1K coffeetech electric roaster. I have been happy with it, and have been told by others that the coffee I'm roasting is is very good. I roast in an outbuilding because I don't cool the beans in the roaster. I made a stainless mesh tray that fits over a duct with a fan that sucks the heat and smoke out and cools the beans in about a minute, but there is a fair amount of smoke when I dump the beans into the cooling tray. I roast 10-15# a day for our shop.
The electric elements are very effective and consistant. once preheated to the proper temp, they roast a batch of beans without much change in temp. But it has no temp control, the elements are only on or off. There is a thermostat but it is not to do anything but shut the roaster off if it overheats. I use preheating and fan to regulate temps.
Since I haven't roasted on gas, I can't compare. I would like someday to have a larger gas roaster, to be able to roast in my shop.