I'm a CyanogenMod user, but I don't think they're a serious player in the Android community.
Cyanogen split from their first actual customer, OnePlus, after a partnership that has been described as "rocky." I don't know what the problem was, but that sounds to me like the company isn't capable of meeting its customers needs.
Beyond poor customer service, the developers do not appear, from the outside, to have any experience project management. There was never a stable release of CyanogenMod 12.0, and hasn't been a stable release of 12.1 yet either. A reasonable release process would probably involve a code branch containing their tested, stabilized add-ons that they integrated with AOSP. New features should be developed in a separate branch and merged after they've been through testing, and during a window that's open after a release of the stable branch. None of that appears to be happening. The changelog for their nightly builds is a firehose of bug fixes and new features.
And beyond THAT, I've never heard of Cyanogen working to push any fixes upstream into AOSP. I would love to hear that they do. If not, they're building a patch set that will only grow over time, which will eternally increase their workload of integration with the upstream project
It's unsustainable. And that's sad, because I like one or two of the features they add to AOSP.