Is the magnetic timeline on Final Cut Pro X optional? I see the advantages of the magnetic timeline, but nonetheless still prefer dedicated layers as it gives me a much greater sense of control of specific kinds of resources. I have been considering Final Cut Pro X but if the magnetic timeline is imposed upon its users, or if it is optional but there are no significant layer controls when magnetic timeline is disabled such as hide/mute, etc., it's a complete showstopper for me. I'm coming from Sony Vegas Platinum HD 10 to which I migrated from iMovie, and right now Final Cut Pro X looks like going back to iMovie.
It's not optional. However, in use, I think you'll adjust and have the same sense of control very quickly. Have a look at the various online tutorials. I found this one exceptionally helpful http://www.izzyvideo.com/final-cut-pro-x-tutorial/ Also spend a little time with it and you'll soon see it's not anything like iMovie.