I have, but only needed it when dealing with Blu Ray rips and movies with file sizes bigger than the 4 GB android file system requirements. Other than that its played all avi, mp4, mkv, and xvids that I keep on my HTPC without modification. The only downside is I have'nt gotten subtitles to work properly yet. It doesn't recognized SRTs and when using handdrake you can't burn i SRTs when encoding.
If anyone knows a good method to do SRT burn in let me know
Ok I just found this if anyone is interested ?
How to convert videos and transfer them to the Samsung Galaxy Tab - Know Your Cell