Average? I've used it at least a dozen times in the last month, and it's worked perfectly every time. It may not be the fastest, but it's certainly the best... YMMV, of course.
It's good but considering auto-reply feature of Gmail and integration with other apps like Calendar and Hangouts, I wouldn't pay for any such solution.
Of course, assuming the organization use Gsuite else, maybe x.ai fits the bill.