A quick comment on AE vs FCP. AE (After Effects) says it all. I had 38 people working for me doing post and hands down the person using AE to edit took 3-4 times longer. It was never designed to do that.
Motion vs AE: Motion is cool because it is in real time and it is easy to use. However, it is buggy and often crashes. AE is solid and many times I find myself excited by early progress in Motion only to become disappointed by Motion’s instability as the project gets larger.
AE and Motion are tools for post editing. Being in Hollywood and working with several post production artists, I can share with you that not one used Motion or AE. All of them used FCP.