Sounds good to me, similar quality to other ones I've heard and there's real intelligence behind it, unlike Siri. I look forward to when I can try them out in my car. Grok is already helping to answer the never-ending, progressively harder questions my older kid has started to ask during long car rides.
The voices sound robotic and weird as always. The interesting part was how each example distilled down "business" into a comical post-modern sound bite. "Don't worry, we've taken the extra charge off your account."