I've been looking at the LA40B650 TV recently, espcially as it has some interesting media playback features over DLNA and USB. Tried some samples out in a store with mixed results.
Original off air Freeview|HD TS Streams
* 576i - Don't work
* 720p - Work
* 1080i - Work
MP4 files - work
MKV Files - work, but some seeking issues
The one issue I did discover is you have no aspect ratio options when playing back over USB. The only two options are "Fill" or "Original". Some of the MKV files were 4:3 or 2.1:1 aspect ratio.
Anyone here had a play with this set and various media formats?