Well I just tested this on a simple project, and Logic Pro X does indeed organize by Roles, sort of. It takes a single Role and randomly splits it into different tracks, chooses to show only half of certain audio regions, and shows a video frame that does not play; double-clicking the video and manually dragging to preview shows a completely different part of the video than that which corresponds to the project exported from FCPX via XML. I wonder, could this be any less useful? I'll test on different projects now to be sure.
A subsequent test yielded slightly better results, though Logic continually asks if I want to convert to 23.98 as opposed to the project's native 25 --even though the project is already at 23.98. Importing the XML into FCPX from Logic, I find it ironic that it places all audio and video as connected clips, ignoring the magnetic timeline completely. As cool as Logic Pro X is, I hope we get some actual audio mixing tools directly inside of FCPX, because even though sharing XML files with another program is pretty straightforward, it is just another unnecessary, and somewhat messy, step in the process.
"Any chance you could post a screen shot of what the project was in FCP...?" Unfortunately, no. I duplicated a client project and tested with that. She would not be thrilled if I shared with the forum first
to add something on tpayton's comment - it is not the version of the xml which matters. it is the type of the xml. this can be found in the <!DOCTYPE> tag.
apps maybe can read several types of xml but maybe export only one type.