I use it, it's precise, and has tons of power. There are lots of videos on the site to explain how to use the features, whereas I mostly concern myself with the direction of the sun/moon and rise/set times. But yeah, it's cool.
Another one to consider is Sun Surveyor. I prefer it over Photographer's Ephemeris due to the extra features. I find myself using the augmented reality mode a lot to predict when the sun will poke through the clouds.