As an early user of FarmLogs (and as a programmer), I found it really useful. All I wanted to do was find out average rainfall on my land and make a way to denote the prime spots for crop planting on the land (purely as a hobby). It was super useful and intuitive for that, something that I couldn't get to make happen easily trying all sorts of things with Google Maps, various mapping APIs, and Google Earth.
As another farmer and programmer, who isn't based in the US, I have found all of the most desirable features (like rainfall data) are not available. I have tried it out, but there is nothing that keeps me coming back. 20% of American row crop farmers is still fairly impressive, but it will be interesting to see how they try to approach the rest of world.
