I think the DSM-520 is an exceptional product, except for the album art and the picture scaling. It is also very specific on what it can and cannot do, both in the manual and online.
Advanced Simple Level 5 for you MPEG4 people. That means, max bitrate of 8K for the video portion. No Quarter Pixel and no Global Motion Compensation. It however does not care about Adaptive Quantization and it does not care about B frames - plays both fine.
It even does some things not listed, such as playing ogg files that even hit 700 kbps or higher! I'm a fan of using ogg's that have special tuned engines behind them and this thing plays it like a champ. These are things that I cannot get to play on a SlingBox for example. The SlingBox pukes trying to play them.
Other things is, it does not care about resolution of your vid. Feed it a 1080p stream and it will eat it fine.
So I can't see the comments about what it doesn't do being valid. If you follow the rules, it will play your file and works as advertised, except where mentioned above. If you download movies off the net, and they are AVI's, be warned that a lot of those guys use XVid and they will enable those unsupported features. I have yet not had it play soemthing where I followed the rules. If you need the bandwidth, use MPEG. It will take a 25 mbps file on MPEG-2.
Crud. I even have this thing feed AC3's to my proc.
-X