I've got the Farm Innovations and so far it is great. I'm only on day 5 of my first batch so I can't say much about hatch rates but the temp has been rock solid and humidity has been easy to keep steady as well. It's cheaper than the hovabator by quite a bit. The main criticism you hear in all the reviews is that the built in thermometer and hygrometer are inaccurate and that is absolutely true - they aren't just a little off - they are a LOT off. But "Reference Only" is printed in big red letters on them and a separate glass thermometer is provided to be placed in the incubator which IS accurate. Honestly you are going to get a second thermometer to check the accuracy of any incubator's built in thermometer anyway, so I don't see this as a huge negative as long as you are aware of it.
I saved $75 by going with the FI instead of the Hova, and a $3 digital thermometer/hygrometer solved the only issue it has. Seems like a deal to me. Of course if money isn't an issue the general consensus seems to be Hovabator.