At Mux we use Cedexis Openmix to dynamically select between Fastly and Highwinds (now Stackpath) CDNs to stream a lot of video. The end-user experience with a CDN is going to vary dramatically depending on where your users are located around the world, which ISP they use, and many other factors that change by the minute. I wrote a blog[1] post about how & why we use multiple CDNs with our video service.

You might also want to evaluate a video QoE service to see what your users are experiencing in terms of video start-up times, rendition switching, buffering, etc.

[1] https://mux.com/blog/multi-cdn-support-in-mux-video-for-impr...