Hey Jack,
Now that you say that, I think there was a download. My partner did say that he saw some update when he played it on, I believe, Monday. This is when the Vive started working fine.
I checked the news on the SteamVR app and there wasn't anything released so if there was an update it wasn't documented.
It does coincide with my belief that it comes down to firmware and software. I checked the post on the last community announcement and have seen a few people complaining about tracking and shakiness.
I understand the aggravation about software. So many different variables that you can't test for. Unfortunately, this testing does come down to the users and it is up to us to try and diagnose as much as we can. But, this is what I love about adopting new technology.