Early versions of the Maha/Powerex MH-9000 had a reputation for
occasional shutoff failure - they would not detect full charge
reliably, and the batteries would become quite hot as they cooked
away. Powerex revised the charger - I think they tweaked the firmware
logic having to do with the shutoff detection - and I understand that
they *raised* the minimum recommended fast-charge rate from 0.3C to
0.5C. Presumably this results in a more rapid temperature rise at
full-charge, and makes it easier to detect.

MAHA told me they've never revised the firmware (which I doubt). I've had no
termination-failure problems, even at 0.1C.