As a developer I love their tools for creating experiences to be used on-stream, and the interactions with Minecraft are a lot of fun. I just wish that it was easier to promote creative streams on the platform.
I actually loved Mixer when it used to be "Beam". The website was really smooth, and there wasn't any bugs with any browser. Plus, it used to be one of the only streaming platform using "low delay" streaming.
But Mixer's website is full of glitches if you're not using Google Chrome, and I really can't understand that.
And I don't really see any advantage of using Mixer while Youtube & Twitch are here, and are allowing low delay streaming