I own a Dune D1 and a Dune TV303D. The TV303D plays everything I've got, but it doesn't downmix TrueHD only DTSMA. That's only if you install the patch for it. However, I use it in my living room with surround sound so that's not an issue.
The only reason why I like the Dune over the Mede8er is due to jukebox support. I can use Zappiti or Yadis, which both support Movies and TV Shows, but with the Mede8er you have to use two different programs one for movies and the other for TV Shows.
I'm also changing the way I'm ripping my movies that have forced subtitles. If the movie has forced subtitles I rip it with ClownBd as folder structure, and then use MKVMerge to remux it and flag the forced sub track so the my Dunes will recognize this and play it accordingly. Again, you will have to install a patch that was made by one of the forum members.
I'm not sure if the Mede8er can recognize forced subs.