I was looking at the Herpstat Pro, but went with buying two Herpstat II's since I'm uncertain if my long-range plans permit me to keep all of the enclosures together and within the same proximity. I have a few Helix's but the wattage that a Herpstat can take is higher than a Helix, and the wattage a Herpstat II can take is higher than a Herpstat Pro. Figure out your wattage and look forward as much as you can into the future insofar as location of the racks, etc, and then make your choice.