The 200D is better. The difference is how the proportional control circuit works. The 200 works like an ultra fast on/off style thermostat to control the heat source while the 200D works more like an automated dimmer switch. (better control and better for heating elements over time)
Honestly though the herpstat line of thermostats are better than the VE thermostats. The herpstat intro + is cheaper, safer, and slightly more accurate than the 200 or 200D.
Reply With Quote