While I do not have exact data, I believe micro HDMI is more widespread than mini HDMI not that either is widely used. Just out of my own devices, the Kobo Arc

While I do not have exact data, I believe micro HDMI is more widespread than mini HDMI not that either is widely used. Just out of my own devices, the Kobo Arc 7 and the One Mix 2S Yoga both have micro.