I don’t really have a feel for what your needs are outside of creating a cartoon look Lawrence, so I can’t speak to how valuable Motion would be to you in the long run. I can say that learning Motion (or After Effects or any compositing/Motion Graphics package) ultimately pays off even if the package itself might not be your cup of tea.
Things learned in one package-the fundamentals of compositing-work no matter what software you use. If you really want to do this kind of work, then that’s the sort of knowledge you will need to acquire. Fortunately its pretty much the same approach regardless of which package you use. Blending modes, masks, keyframes, these concepts are ubiquitous. Doing it in After Effects is similar to doing it in Motion. Some features in After Effects (like the puppet tool) don’t exist in Motion and can be indispensable depending on the type of project you’re working on, but similar effects can be achieved in Motion (just takes some ingenuity, creativity and trial and error.)
What do you want/need your software to do?
“Whether you think you can or can’t, you’re right.”