Funny how both of mine have never had any of the issues you have had. Both have played 1080p at 60fps just fine (soccer games mostly) and 1080p24 and 1080p29fps (movies encoded ~10-15mbps all encoded with x264) just fine without studdering/dropped frames. Even the anandtech review seems to support this a smost of the files it "failed" on just arent supported. Or have issues such as DTS-MA audio only being DTS which resulted in a lower score.
Only issue i have had wasnt even WD's fault but with the headers from an old version of mkvmerge when i remuxed my audio. Well that and lack of DTS-MA support
No comment on the 3d but i didnt even know they supported it!
All that is played off a WD passport though. Streaming wise might cause it to have issues. So if you stream your experience most definitely could be different.
Guess my experience has been much different than yours though. I've yet to run into files the WDTV couldnt handle other than issues caused by other programs (mkvmerge) so to each his own!