I don't know what version number, but when it was new I could depend on it to do things like sending SMS while driving, changing the navigation, etc.
Now it's barely worth attempting, because it gets it wrong more than it gets it right.
I definitely notice there's a difference in quality depending on your network latency I thought quite a bit of the processing was done locally now, but latency seems play such a part in its quality.
On macOS it still seems pretty good - I have carpal tunnel syndrome and by Thursday or Friday most weeks I end up using Siri to dictate not code but a lot of conversations in Slack, pull requests, iMessage, etc. In fact, I wrote this reply with Siri right now.