There is also Metrix out there. The guys behind it were the original programmers of Preps back in the day. I haven't used it, but have looked at. And it looks pretty good. The shop where I work is a Kodak shop. Workshop and Preps.
Here's a link to Metrix's info: http://www.efi.com/products/productivity-software/imposition-layout/efi-metrix-planning-and-imposition/overview/
Here's a link to Metrix's info: http://www.efi.com/products/productivity-software/imposition-layout/efi-metrix-planning-and-imposition/overview/