I use both. Both are excellent thermostats. The helix is simple to use cause there isn't many options on it and can only set the temps one degree at a time. This thermostat has a great track record being used for many years.
The Herpstat is also a great thermostat that offers many options already built into the thermostat. you can change temps by 1/10 of a degree which is great for incubators, also has a high and low temp level alarms that is also 1/10 of a degree settable, my incubator is in my basement and when I'm upstairs and my daughter opens the incubator, I can hear the alarm upstairs. When temps hit operating range alarm stops, it is cheaper. Plus many other options.This would be my pick if I had to say which one I liked the best. But they are both very good thermostats.