Not me. However, I starting planning for a new product that needs to scale to reliably hold a lot of measurement data. I initially was thinking Cassandra might be a good fit. After doing some research, I like the design of CockroachDB better.
I'm also looking at this project for a similar use case. Have you looked at InfluxDB or Prometheus?
Take a look at druid
(cockroach labs here) No one is yet using it in production, but we're actively seeking beta clients. If you'd like to talk more, feel free to ping me: jessica @ cockroachlabs
If you spend some time using it now, you will find its not ready yet.