The build system we have now is significantly better than what was available at the time he mentioned (September 2007). IIRC back then the local machine was a significant bottleneck in dispatching work, storing intermediate build products, and running tests. If you weren't around then, send me a mail from your work address and I'll tell you about when we had to walk uphill both ways in the snow.
Now, build times are not a major loss of productivity for me. In fairness, I don't work on the same system he was working on, and presumably not the same as you either.
I'm a Google C++/Python programmer who has (mostly) switched to Go for new development. Rob's statements about C++/go compilation performance are still relatively correct. The client libraries are sufficient for many, but not all projects.
I think what most people don't appreciate is how cleverly the Go team at Google established a reasonable migration path for internal developers. Some systems have migrated far more quickly. hopefully, we'll see some papers describing the migration at some point.