I have 3 DIY GQF, knockoffs. 3 Little Giants, 1 Farms Innovators Model 4250 Pro Series Digital, 1 GQF 1588 and 1 Nurture Rite 360.
Naturally, the cabinet bators are the best. The foam bators are harder to dial in, all three of the Little Giants were "still air" when I purchased them, I installed fans in all 3 and auto turners. They are ok for the money but very unforgiving if conditions in the room their in has extreme fluctuations.
The GQF 1588 is a little better than the Little Giants. Once their dialed in, they tend to hold temps steady.
Out of all the foam bators, the Farms Innovators Model 4250 is the best in my opinion. Holds temps once set, holds humidity reasonably stable. It has a count down to hatch day that can be set at whatever day your eggs will hatch. Although, it's not cheap, it's not that expensive from
TSC at $140.
The Nurture Rite 360 is the worse of all of them, even though it looks very well made and has no problem holding temp and humidity. The auto turner quit the 1st week of incubation. It also has no fan guard and other people report chicks getting caught in the fan. I also noticed development of the eggs wasn't as good as eggs that were set in a upright turner. It would still turn the eggs if you pushed the buttons to test but not automatically. It also has a count down timer on it, it will automatically stop turning 3 days before hatch day but I don't know that, seeing how mine quite turning within 1 week. In my opinion, it's not worth the purchase price from
TSC at $155