My primary source of music recently has been a Subsonic server that I set up on my HTPC. While I originally learned about Subsonic through the Android app market, I haven't really used it on my phone as most of the time when I was using the phone to listen to music I was riding the subway and unable to stream. I did notice that performance was laggy but as I was using Subsonic to stream to my work computer phone performance wasn't a concern.
What did become a concern was delays in the menu system and queuing tracks through a browser. At first I assumed it was because I'd set the memory limit allowed to the server too low but raising it didn't solve the problem. After a visit to the forum, the problem became more apparent. Subsonic runs into difficulties when accessing network files when running on Windows due to some incompatibilities with Linux based NAS devices. This isn't that unusual of a problem, Windows doesn't play very well with others. Vista over wireless had a habit of overwhelming some of my NAS drives to the point where they would slow to a crawl and start spiking in temperature. Windows 7 is not as a aggressive but took registry hacks in order to even be able to see some devices without the use intermediary software.
My music library happens to sit on my first NAS, which is several years old. Its slow to begin with and it keeps the drives on it spun down to reduce heat. There doesn't seem to be an easy fix so it looks like my music library is going to go on the HTPC with the NAS running as backup. Considering how cheap hard drives have gotten it isn't a big deal.
With luck, Subsonic's woes will be fixed up once the server doesn't have to deal with the network anymore. I am really hoping that it isn't Verizon's POS router that's been causing problems. It recently started acting up whenever network volume increased, basically ceasing to provide any DNS functions. That problem, at least, seems to have been overcome by using Google's public DNS server 126.96.36.199 as a secondary DNS option in network configuration. The router is kinda required in order for the cable box to function properly and connects to the Fios box over coax rather than a regular network cable. While its possible to run a regular cable to the Fios box it would take a service call to Verizon to do it. Sometime next month I should be getting a TV card that will let the HTPC replace my DVR so I've been waiting to take care of both things with one call.
Update: Changing to a local drive completely fixed Subsonic. Like night and day. My phone connects perfectly and playlists update almost immediately.