I don't agree with the notion of not buying the demo. Because I believe if this guy cam get that out of the keyboard and its satisfactory t me. I know I can get that and more.
All the TOTL arrangers have excellent demo sits and sounds. A decision can be made based on them if one feels they are competent enough to play what they want to.

I found the Roland Namm Demo pretty lame. Especially the Guitar demo. But i would not discount the keyboard becasue of that. For me its all about the sounds first as I use a DAW for recording and am only using the arranger for ideas and like a real arranger would be hired to flesh out a song.

David Foster, Maurice White,Michael Omartian.....All Arrangers a songwriter/performer uses to complete their songs. I may only use the bass line of an arrangement. I can arrange strings so I would probbaly do my own string arrangements, But would use horn arrangements from those who can do that better in styles.

Yamahas do too much for my tastes including the final mastering. Their output is indeed compressed cD quality already. Which is great for someone who does not have or care to deal with Mastering.