You'll find everything here:
https://www.mobileread.com/forums/sho...d.php?t=256283
Kuskro is recommending there last year's firmware but the 1.7.3. update from September is works fine as it is.
I wouldn't mind if the M96 was a faster device, but it's good enough for the pdf's I'm reading. I guess a fast and responsive large screen e-ink tablet is still to come.