If you need this its a mixed bag regarding codec support, and I found the issues with other servers made the solution less viable. From my perspective, I needed something to access my library, rather than rely on hardware specific transcoding. The only thing I can't comment on is transcoding I assume their clients manage this. Don't want to name names but I've pretty much tried them all. Plex takes a while to run through a big, say 3tb collection but it genuinely has been the most painless and reliable of all I've tried and the searchable options are far more varied and sensible than those for others. This may sound set up but save yourself the pain and effort and try Plex first. I have an iMac and MacBook Pro both running Mountain Lion, and the iMac now serves my xbox, wdtv live and archos 7 faultlessly.
Plex server is totally free but you can pay for mobile clients.
But then last week I found a poster who recommended Plex media server and its so good I'm trying to find the post and poster to thank him. I've had this same frustrating hunt for ages, tried and found all of them to have serious issues either with usability or actual functionality.