The staff at Spike often uses the products on their own homebrew! We've had a chance to use the heater that we sell with our conicals on mulitple styles of beer and it works wonderfully!
Whether it's a Belgian beer that needs to finish out at 80+ degrees, or keeping the conical warm enough in a cold room, our heater does a great job! Installed around the cone, inside the jacket, it keeps yeast warm the most direct way possible. During fermentation, yeast will often flow to the bottom of the cone and back up the middle of the conical. This is why we position the heater here, so that yeast can pick up heat along the path where they congregate the most. This is also keeps yeast from flocculating in the cone prematurely, due to the added heat.