okay well I actually got mine delivered today (surprisingly quickly, given that I only ordered it yesterday). Here is the good and the bad:
I have about 60 movies on my NAS running the Plex media server (all 1080p, with subtitle tracks on most, and chapter marks).
Inside plex app from the samsung store:
Cinavia DID kick in and disable playback at the 20 minute mark when I played "the other guys" off this list:
I could NOT get any subtitle tracks to be recognized by the player inside Plex on any of my files. I know they are there and play fine if I play it on my computer's Plex client.
Besides these two issues, the samsung player is solid. Every movie I attempted to play that wasn't flagged with cinavia The picture and sound are perfect. There's 0 CPU usage on my NAS running PMS because the samsung is able to play the clips without trancoding.
Inside of plex, the transitions are not as smooth as they are on a computer. This appears to be a limitation of the app itself as it is only 3.5 megs and the Windows7 version is about 60 megs.
So sadly, cinavia is a big issue on this, if anyone knows a way around it, I'm happy to explore it. it seems if you want a totally compatible home media streaming experience, the mac mini or equivalent pc is the only way to go.
EDIT: I tried putting the same movie folders onto my flash drive and play that via the USB interface in the front of the player. When I did that, the subtitles were recognized on a some of the titles. Chapter selections are still not available (but fast forwarding and rewinding works). Audio language selection worked for each title.
I had a 1:1 copy of "the sessions" converted to MKV via MakeMKV which did not allow selection of the embedded subtitle stream (I observed this same behavior on the Sony S590)