We were interested in CockroachDB because a few of us had experienced it long ago with Postgres and that was one of the attractions. However, there are limitations to the exact compatibility. My advice to others is before you choose CockroachDB it would be good to check if it does everything you typically use in Postgres. Cross-check that it doesn't miss something you want or need or are very used to. We used CockroachDB on a small scale and it's been great. Nominally it looks really good. Our fear is we'll scale it up and it won't scale. However, it is supposed to specifications are great. We've done spiky testing and it's never been a problem. I rate CockroachDB an eight out of ten.