Yes I've listened to both in the Ayre factory demo room in Boulder. Frankly the two sound almost identical playing red book cds. Probably the C5 is slightly better on top but the bass authority, tonal balance, and sound staging are very close. The C5xe is slightly more dynamic.
The big differences between the two are what they do. I just purchased the C5xe because I'm interested in stereo and SACDs. If I was more of a videophile or interested in 5 channel surround I would have purchased the D1. Buy the way I did demo the video part of the D1 and its picture output is better then any DVD player I've ever seen, but take that with a grain of salt since my video exerience is limited (I have a HDTV screen but no HDTV sources.)