@Clondalkin - Basically sir more on movies ang balak ko...ngwoworry lang if it can smoothly play high bitrate HD movies..yung mga 40-50GB movies..kayanin kaya ng Xtreamer to?sa internet naman..maybe some radio stations and a little of youtube videos..thats it!!
I think both will be OK in terms of playback.
BTW, those 40-50GB pure BD rips are much lighter on a media player/streamer than those high bit rate 1080p MKV. I guarantee you. It seems the compression to MKV is adding a lot of burden to playback because the device needs to decode the file first, whereas, if it's a pure BD rip, "derecho" playback. Well tested ko na eto sa Egreat 31B and Mede8er and maganda talaga ang IQ/PQ if it's pure BD rip. The Mede8er even supports subtitles for pure BD rips. But, and there is a but, the main issue is, can your player at least downmix DTSMA/HD or TrueHD? If it can pass-through these HD audio variants then even better -dito magaling ang Egreat 31B naman.
So here are your considerations:
Realtek based players: No HD audio passthrough yet (puro unfulfilled promises palang and walang linaw if this will ever happen sa current gen players). Likely capable of DTSMA/HD downmix to DTS, but probably not capable of anything with regard to TrueHD.
Sigma based players: More likely capable of HD audio passthrough because older gen players like PCH and Egreat are capable of this nga. Should be able to dowmix DTSMA/HD and TrueHD as well. Hence, the WDTV Live might be the better device on this regard, or the one that has better potential.
As for secondary functions and features of NMTs, I'd rather not comment too much except to say that the PC is so much better and reliable still.