When it works, it works well. But 20% of the time, there are issues. Either the videos are not uploading for days, or playback doesn't work and the video keeps buffering. Support takes days to respond. This makes it way too unreliable.
But what really bugs me is that the minute the AppSumo deal ended, they started showing advertisements (i.e. self-promoting their platform by way of an overlay over the video you share with your colleagues, clients etc.). So despite customization options and CNAME etc it's not white-labeled anymore. It only happens since the AS deal has ended and they're safe from bad reviews. What a despicable practice.