I came across this thread while looking for something else but thought I'd relay what little info I have.
I don't have a DMS1, but I do have a DMP1 from Rockford, and yes, SimpleCenter is a pain. However, there is a pretty active community of users working on mods over at:
http://finance.groups.yahoo.com/grou...guid=233021899
In particular, a version of SimpleCenter has been hacked/modded to surpase the 10k song limit. If I recall correctly, the limit has been bumped to 50k+ songs. Several other major improvements have been made as well. Look in the "Files" section of the group for the newest update.
On other notes, I use a J River's Media Center software:
http://www.jriver.com/
It supposedly does upnp serving. I don't have a upnp device yet, so I haven't tried it. In their forums there is a thread talking about what devices its been tried with and compatability. I believe they claim it works with the DMS1.
The software isn't free, but IMHO worth the money. I've been a paying user since Version 8 and find it completely indespensible for managing my 16k+ file library. I use it my home machine, office machine, and laptop (legal under their licensing). I use it at home with a remote as a media center type software to listen to music and watch video. It has library serving and client capabilities, expandable, etc.
I know these kinds of things always come to personal preference but I highly recommend the software. Oh yeah, it is Windows only, so that doesn't apply to those of you who have the luxury of chosing another OS.