I have a GQF cabinet incubator I bought from craigslist. It's in perfect condition and fairly new. The controls are so hard to get just right. I have a digital thermometer 'spot checker' from brinsea and the temp swings are scaring me to death and perhaps killing my test batch. After setting it at 99.5 with the off set to 99.7 and the on set to 99.3 I wake up in the morning to it being 97.6 or something equally scary and I know it's been too low during the night. I just opened the door and fanned the eggs when it got up to 100.3 tonight. it's freaking me out after using the Brinsea Octogon 20 and it self regulating and staying rock solid at 99.5-99.7 for 21 days. So what swings of temp do your eggs survive? I've moved the incubator to a new location, hoping this room, while a little cooler, will be more stable in terms of room temp. I'm hoping that helps. We will see tonight.