I had the opportunity to work with Ragtime a while back. My feeling was it really came into its own with things like database publishing. So for things like parts catalogs, user manuals, and other publishing tasks that needed automated style-sheet driven formatting, it worked quite well. But for traditional prepress work, where design, appearance, and typography were critical, it fell far behind what you could do with Quark or InDesign.
In many respects Ragtime reminded me of Interleaf (for those of you old enough or unfortunate enough to remember that beastie) in the way it approached publishing.
Not a bad program. But I couldn't personally see buying it for anything I do.