6 years of development and deployed to actual products is an experiment?
The issue I have with Google is it's never clear to outsiders when projects are simply "experiments" that google is going to kill later. Dart, GWT, Angular Dart, for example, seemed like more than "experiments" yet google did a soft kill on Dart and effectively a hard kill on GWT.
You learn that something is "an experiment" when all the sudden updates slow or stop and the mailing list stops getting responses.
I don't trust google software because google bureaucracy is fickle and unpredictable.