I am definitely using Weave Net for my trivial single-node cluster because it was the only CNI option that included a one-liner to install.
I have never had any reason to try a different one, the pods can talk to each other, "does what it says on the tin"... and on top of that but unrelated, their webinars tend to be star-studded and very informative.
BTW Weave Net has been “docker pull”ed 30 million times. _Somebody_ must be using it...
(I work for Weaveworks)