Its been a while since I've posted, but the NMT has come in! It seems to be a pretty solid little device...it can definitely handle the HD stuff I've thrown at it so far (1080i MPEG2 cable TV). On the other upsides, its cheap and the development team is really VERY responsive. I posted a reasonable feature request to their forums, and they replied within a day saying they'd add the feature. Less than two weeks later, they released new firmware with my requested feature!
Now some of the downsides. Firstly, it can't decode all audio formats! The DTS audio technology has to be licensed, and since the manufacturer doesn't pay the fee, they just output the audio digitally as raw DTS without decoding. You need an audio receiver to do the decode. Luckily, I don't have any material that is DTS encoded. Secondly, the system is far from perfect in seeking, FF/RW etc. There is no backwards seeking for MPEG2, and the seek/searching is a little buggy in general. Sometimes when I press play during a fast forward, it will just return back to the beginning of the clip (REALLY annoying). Another issue I've found is that certain combinations of container format and audio codec cause the audio to not be recognized or played back. I've found that when I use VLC to transcode to their MPEG2 PS, any AC3 audio is not recognized. When I use ProjectX, the generated "m2p" file's audio is recognized. The terminology is kind of muddled for me, as there are MPEG2 PVA, PES, and PS...and I'm not sure what VLC or ProjectX are really doing under the covers.
So basically, this thing is really still a work in progress. It still has lots of issues and bugs to work out with the different container formats and seeking, but they are regularly releasing firmware updates and I am really glad that they were able to go ahead and release this product to the market.