Speech-to-text has to still go a long way when it comes to foreign accents. Google now's "Ok Google" initializer has about 3/10 hit-rate for my Indian accent speech.
'Ok Google' is a different problem though - needs to be a low resource, always-on listener with a low false-positive rate. That's quite a different problem space than general speech-to-text.
I think I get about 50% hit rate with 'OK Google' and I'm a native English speaker :).
