I tried out a Popcorn Hour A-210, trying to connect it to a Windows home server and it was terrible.
Lots of people think they're wonderful and maybe it's my fault but I found it to be horrendous. Hanging while reading meta data, getting stuck in loops of error messages, freezing on MKVs that played back perfectly fine elsewhere. Not to mention that the whiz-bang interface only supports one network share! I had that 'beta software' feeling, not that '£200 of quality, dedicated, device' feeling.
Companies need to understand this should work out of the box with an easy to use, attractive, accurate, interface and not a list of network locations and filenames or mismatches.
Media Browser on the PC is a good example. Tell it where your stuff is and it'll never bother you with the detail again.