I have migrated all of my mixes to Stream, and although it's worded as if the move from Mix to Stream is an upgrade or improvement, we Mix users loose a ton of functionality. Here are some examples,
1. The table of contents feature when uploading a Powerpoint to Mix is very convenient for people to find a section of a lesson. I don't know if it's possible to create this in Stream. Stream doesn't even give you the "youtube" thumbnail when you drag across the timeline bar at the bottom of the video.
2. The analytics in mix allowed me to see how long a user spends on each slide of a ppt, and how long they watched the lesson. I don't see this function within Stream. I cannot tell who has logged in and watched my stream videos.
3. Uploading to Mix was MUCH faster than having my PC make a video, then uploading to Stream. This process seems to take forever and the file sizes are huge.
4. Small changes in a PPT, then uploading an "existing mix" was very simple and fast process within Office Mix. Now, when updating a PPT, you have to reconvert the lesson into a video. I have a good/powerful PC and a 1 hour lecture takes a long time . . . this process was MUCH faster using Mix.
5. The download link was nice in Mix, so I could download the original presentation off of the Mix site.
I don't know if it's possible to keep the mix features and functions as an option within Stream so users can chose to either stream a video or play a PPT mix. I do, however, appreciate the ability to do any of this within Office365 and I understand that there are other factors that must play a role in eliminating Mix.