I am looking at Apple Motion and Adobe After Effects. How to they compare to one another? What are the pros and cons of each?
After Effects is much more powerful than Motion when you get into advanced stuff like scripting your animations. After Effects is much more tolerant to large projects, and you can "precomp" different sequences (which is difficult to explain without you actually seeing it; basically allows you to put one timeline inside of another or reuse a specific portion of your project over and over, if that makes any sense). Apple Motion only allows one timeline per project, you cannot nest sequences inside one another without rendering out a QuickTime movie.
Apple Motion does however boast that it gives you "realtime previews" which plays your animation instantly, whereas After Effects typically requires you to render a RAM preview in order to see your animation in realtime. Of course this depends on the speed of your computer and the complexity of your project, so this is really only handy for simple projects.
When you want to start doing really custom effects like particle systems and other physics based or true 3D compositing, your options are very limited in Motion. After Effects has a whole range of plugins available online that will do almost anything you can think of. The Trapcode plugins are very well-built and very popular. There are very few plugins for Motion compared to After Effects.
I've used both for years, and Apple Motion seems to crash more often than After Effects, especially as your projects get more complex (just personal experience, maybe this has improved as of version 5).
I actually started animating for the first time in Apple Motion, and I agree that the learning curve isn't quite as steep as After Effects (although that was Motion 2.0 and 3.0, and now they're at version 5.0). Once I mastered Motion and dove into After Effects, I haven't looked back. I recently fired up Motion for the first time in a few years and I was struggling to get it to do what I wanted to do, my brain has just been trained to think like After Effects. Even though at first I was more productive in Motion than After Effects (because After Effects is more complex), I have completely reversed and now I feel like I'm a speed machine in After Effects and Motion is now useless to me.
The bottom line: if you're serious about getting a professional tool to do professional work, save up to get After Effects. If you're just a hobbyist that wants to dabble in animation, get Apple Motion (now that it's on the Mac App Store the price has come down considerably).
Hope this answers most of your questions! If you have any other specific ones, let me know and I'll be happy to talk.
I use both. Agree with all of the above for After Effects, I use it for any heavy lifting because Motion just drives you insane if you try anything too tricky with it.
The beauty of Motion is the way it is integrated into FCP. So I tend to use it for things like lower thirds or credits, because I can create "Master Templates" in Motion and import them into FCP and re-use them with different content. For example this allows you to use the same Motion composition for all your lower thirds, but change the text in FCP as you edit.
It's also good for simple things like Ken Burns' effects (panning and zooming on photographs), if you want them to look a bit more polished than FCP's rather sucky motion tools can give you. And being able to tweak things in Motion and see it instantly update in FCP is a lot better than exporting to AE > tweaking > rendering > relinking in FCP.
I have used After Effects, and from what I know, the main difference is that Adobe's has a much steeper learning curve but is also more powerful than Motion. AE is truly like a "Photoshop" for video, and its great for Special Effects. Motion, I've read, is the easiest for making compositions and great if you are working with FCP because it integrates pretty seamlessly.
Again, I haven't tried Motion, though I'd love to use it sometime. You can download the AE trial here.
Perhaps this link proves useful.
Hope it helps!