I've been converting some blu-ray films to mkv for use on my AC Ryan HD mini. I chose to include Dolby Pro Logic II audio as a second trac in adition to DTS passthrough. Now though I've discovered that VLC can playback the DTS sound when viewing on my laptop and my AC Ryan HD mini can also downmix, so this got me thinking. Is there any reason to include a DDPLII track in my mkv files? I can't think of any as both VLC and AC Ryan HD mini plays the DTS files fine, but I thought I would ask here incase I overlooked something.