Right - that is encouraging - and it seems I am wrong!!! You might want to sticky this somewhere for the other SONY TV users.
After more fiddling - I have got two exclusive scenarios which work differently and give different results.
One hi def no transcoding (assuming original files in correct format as previously listed) and one not.
If I select in the DLNA settings / Video:
Mode: Specified Output format (= transcode)
Format: MPEG2/DVD PAL Stream (= stream format i.e. the remux)
Advanced:
Check "MPEG video mimetype override" and then set:
video/vnd.dlna.mpeg-tts
AVC_TS_HD_60_AC3_ISO
The TV will display all the content the server has in it's library - and list said content as MPEG
It will also play it back all be it at a lower resolution that it is stored in, since it's set to transcode via the first setting.
However!
If I set MODE = original (= do not transcode)
Then I set the advanced Video DLNA Override to:
AVC_TS_HD_EU
Hey presto - it works exactly the same as Serviio does.
Full HD render and no transcoding on the server side - problem solved.
Note for others I looked up the correct formats here
"
http://wiki.serviio.org/doku.php?id=sony_bravia_tv"
Click on the appropriate year and you will see a list of all the DLNA profiles your TV will support.
You also need to correctly encode the video files before hand. H264 AAC is the smallest and highest content combination hence why I listed how to do that before below.
Right I am in for a purchase then. Awesome product!