I have a 15+ year old still-air LG incubator, basically the same model just dingier, lol! I've used it to very successfully hatch out quail eggs, the main thing is to get the temperature regulated... this means setting up the bator DAYS before you plan on putting eggs in it. A HUGE help is having it in the basement where the room temperature does not fluctuate much at all. It is a fairly tempermental machine and you do need to get the hang of it, get the temperature right and then leave it alone... adjusting the knob even half a hair makes a big difference. A lot of people give it bad reviews, but once you get it working for you it definitely works well.
This will be my first chicken batch (starting this weekend) and I"m using some cheap local eggs as a test hatch before I order the expensive eggs, but have had 100% hatch rates with the quail eggs.