Apple Motion works pretty well with Final Cut Pro X, my mainly video edit software. Using both programs let me create great templates that makes my life way easier while editing. Another great point is that the interface looks a lot like FCPX, so it is very intuitive for professionals like me.
I fell Motions can bring some of the effects from Final Cut Pro, once I needed to recreate the "bad tv" effect since it just doesn't exist in Motion. Also I miss a lot some key features that I can find on After Effects, mainly for complex annimations. I know that there are some tolls for that but they are not intuitive. Another problem that I found using Motion was on sharing my projects: I couldn't find a way to let people with older versions of Final Cut Pro use my presets... I would love to see ways to export for any Final Cut Pro X version. Last but not least, some times while I am editing my templates on Final Cut, I find the app crashing, it cleary happen because of the file I created on Motion, but I can't figure out how to fix that; most of the times I find myself exporting twice to check if the second file will be out of crashes.
My company just didn't switch to Motion, cause we still needing to use After Effects for some creations. But we would love to use just one software.
While working at HeyCheff I needed to create some video presentations of our products. At that time, Motion allowed me make some templates for titles and simple animations that I could use across all my campaing, it saved me time and I also could share it with my partners that were editing videos as well.