What I've learned so far with the Incuview:
Temp stays very consistent. Getting the probe in the right place seems to be the key to getting good even temps in the incubator. Corners seem to be a bit warm at times, but within normal limits. Temp bounces back quickly after opening.
Humidity seems to hold well, but I've haven't filled it up yet. Didn't want the humidity too high while the plug was in.
The egg turner won't completely turn large eggs. It turns OEGB eggs just fine. Capacity says 27 chicken eggs, but if your eggs are large you may only fit 22. I've been turning mine twice a day by hand, and switching their places in the incubator.
My mature Sebright pair are as good at producing fertile eggs with good viability as any I've ever seen. 2 1/2 days and they're already getting veiny. One of the easiest breeds for me to hatch, despite their small size.