Ulysses->TextBundle->DEVONthink->Editor, Scrivener, or Word Processor

You make a good point. The problem with backing Pages documents up as plain text or PDF is that you cannot do this in bulk; it is a cumbersome document-by-document process. Additionally, as I wrote here, my writing is varied, complicating things. Pages does not export images with the plain text file like Ulysses does when exporting as a Textbundle document, which can also be done in bulk.