I bought the MBL for 1 week and was desperate to Twonki v5 and my Samsung TV UE40ES6570 
… but…
Very very very desperate and angry 
would upgrade to Twonky v6 or v7 until I saw the new firmware with the new DLNA server option then… Incredible!!!
Now _ with WD Media Server perfect .avi, .mp4, .mkv … seamless play, and complete control of it _ (play, pause, forward and rewind… things that with Twonky v5 could not). So… Great work WD!!! 
In my case there is only improved playback control with .mpeg and .mpg files (I can’t do forward and rewind them) 
Salu2!
