You may be finding that when a large number of employees watch that 'new video' that is being emailed around, they experience buffering problems. The first reaction would be to think that the delivery problems are due to the Vidyard servers.
Vidyard is backed by a global CDN(content delivery network), which is capable of delivering the video content to an extremely high volume of people, at the same time.
When buffering issues are apparent on the user's end, the most likely cause is the local bandwidth available. Even if the internet bandwidth is high, there still could be bottlenecks due to internal networking.
We do our best to adjust the resolution of the delivery when buffering is detected. You should see a 1080p video go down to 360p if it's really struggling to stream properly.
Some information on how we select the appropriate resolution is available here
We would advise checking with your IT team on how much bandwidth is available to you internally and through the internet. They will hopefully be able to run some tests when the streams are occurring to see where the bottlenecks are and take the appropriate action.
You could also confirm that it is an internal issue by going onto a mobile phone and watching the same content on your cell network.