Also, (no point in creating new topic) how difficult are the flourishes compared to the trilogy ones?
A lot of people say that they are easier, but personally I think it's a little deeper than that.
While on the Trilogy you have flourishes like Eko and Tectonic verb(different in their approach), Motion has more sybil-based flourishes. By no means all of them though, and I do not mean to belittle Motion. Motion has flourishes such as symphony and lethal, which again are very diffrerent in their approach, and different to anything on the Trilogy.
It's hard to explain, I guess it's just seeing different takes on flourishing. Different ideas and concepts that make up two different styles. I got Dangerous first and worked hard to improve my flourishing. Then the Trilogy. I use a fair share from each.
I think Motion has some very complex flourishes as does the Trilogy; and also easier ones, if you can do several Trilogy flourishes pick up Motion and vice-versa.
Sorry for the drawn out, jumbled, rambling answer, just writing what comes to mind really.
If you like the look of the Motion flourishes get it, and if you are already fairly proficient, you'll be fine.
Edit: You can always get madness... For a 'taster' I highly recomend it the PDF.