I use it, and have done so since it was a homebrew project for the original XBOX. Those were the days...used to have all the console emulators installed and what not...
Now, it sits on a Windows 7 HTPC, and serves as the media player.
But I will be honest, for how long I have used it, I barely do anything "special" with it. Just the standard playback features and the occasional radio plugin.
Of what benefit is using your own mysql database and such? I see that with the new release coming up, they are moving strongly to interoperability with open source PVR support...but honestly, it all looks like a god damn headache to set up...