Sentry (https://sentry.io/) has been building a load of tracing functionality, and the Javascript client captures logs and requests leading up to an error by default.

I've used this in the past quite a bit, and found it really useful.

And in terms of Cloud Trace vs other tracing providers, I think it was the ease of setup and the simple log + trace inline view that sold us on it. Only took a couple of hours to get working, and it's great that it works for local dev too.