There are lots of written and video testimonials from current mentor students and from current fast track program users that look pretty good. (biggerpockets.com)
It added that «the Preview channel is updated shortly before the full push of our production firmwares» [sic], so any features made available to Preview Program users should make their way to the wider user base pretty quickly. (neowin.net)
The home screen is being restructured again to add user customerisation, with select Insider Program user getting alpha access right now (mcvuk.com)