Synology is a great storage device as well with SHR and all, so its not like if we are using it just for storage we are loosing out something. For movies and videos even I use my HTPC/Media player to playback (not the NAS even thought it has this amazing Video Station) only for Audio I am using my synology USB audio out with E10 DAC. I am also using my rasp pi as my logitech media server even though synology also has it own built in Logitech Server.
When NAS feeds the stream to the playback device all processing is done at the player end. The only thing used and to be of some concern is the network bandwidth, which is good enough for casual videos and FLACS. Only for full HD ISO you might want to keep a gigabit network.
SO I guess you are pretty safe all departments .....
Thanks Sam, with your clarifications I should be safe enough with the 214se NAS. Not sure whether the external DAC feature is enabled in my NAS model but anyway I have a dedicated music-pc along with the Pi, so no issues with the same. Initially I am going to use the NAS for storage and Torrent downloads with feeding to my different players. Will explore more on other features.
I have a Netgear gigabit ethernet port hub along with the TP-Link wifi router which also has gigabit ports. In fact I am at present using the TP-Link powerline adapter (500Mbps) connected to the gigabit port and my Pi in the other room with Openelec plays a 16gb movie file without any stuttering and also a 20gb movie with HD audio plays smoothly but some initial buffering.