Using a EX3 and just moving to PPro, I've resolved to use the MP4 files from the camera's BPAV folder due to the mulitple audio tracks generated by MXF files.
One thing I noticed was that the MXF files on the timeline did not give any indication of any colored bar--not red, yellow, or green. However, when I drop a MP4 file (from the BPAV folder) onto the timeline it always generates a yellow bar, indicating that "playback at full quality will probably be in real time (but it might not be)."
Can anyone explain why this is the case?