I’ve tried a couple of NAS drives as media servers with a PS3:
Buffalo mini linkstation: Worked pretty well. PS3 found it no problem, but streaming can be a little jerky, especially with higher bitrate audio channels. (Be careful the wife doesn’t put a towel on top of it though, causing it to overheat and corrupt the disks and so losing everything!)
GoFlex Home: works well as a backup drive, sh*te as a media server. Takes ages to re-index new files, and doesn’t automatically add them to the public share so the PS3 doesn’t see new files. Once they appear though the streaming seems to be much better than the buffalo linkstation.
To be honest the DNLA server software on NAS drives is pretty sketchy so if it’s an option you’ll proably be better off with a separate server running something like XBMC. Also there is PS3 Media Server which is a free media server dedicated for use with the PS3. I’m planning on cutting the PS3 out of the loop cos it’s too noisy and going to try using a raspberry pi running raspbmc or an older ATV box if I can get hold of one.