Yes really. I did not really believe it until I saw it, but yes the accuracy is there. While you are drawing through the device it will stay within +/- 5°F no matter how hard or soft you pull. I have not seen another device with such a small amount of thermal mass. The 300 watt bulb can heat up and cool down fast. That and the software and position of the temperature sensor give it the the ability to cool and heat another level. The real key here is that it if you draw very fast and then slow down the heater and everything cools down in portion to your daw to keep everything within the set temp range. This allows for accuracy during use... not just an accurate set idle temperature.