My main desktop machine has been running MX for 3 years or so. For me, the draw is that it's standard Debian, comes with all the multimedia stuff ready to go out of the box, and runs well on older hardware. It comes with a nice looking XFCE desktop, which I don't use because I run Trinity Desktop. The custom-to-MX tools look fairly well put together, although I rarely use them.
Actually I'm about to switch to Emmabuntus, not due to any weakness in MX, but because I'd really like to find a Linux that's a workable solution for the average non-Linux user, and Emmabuntus is the best candidate I've seen in a while. Also, this MX installation is getting a bit long in the tooth, and it's time for a reinstall anyway.