I LOVE Sage as a PVR, but HATE it as a music player. This would be a GREAT improvement.
I selected SageMC, but would use any one that has comskip during playback. I preferred Cayars, but it seemed to get a little buggy.
Just to see if we are on the same page, I would anticipate only using the Recorded TV, Live TV and Guides from Sage. Leaving Music, DVD, Media files, Weather, etc all to XLobby. Is that what you are planning?
One additional hurdle I have though (for which there is no good solution) is that I have one MediaMPV client that I would like to use for Music as well as TV.