Just checked the published specs and there's NO CHANGE from 661.
The update doesn't justify considering this a separate model. The Law Enforcement features don't mean a thing to tapers but I suppose this does open a door for them to a new professional market.
The card check compatibility feature and Linear style Retake record function of the MKII could be useful.
As far as improvements that could have been made assuming the same form factor/layout. . . Improved preamp performance with lower S/N, more powerful headphone amp, longer battery run times, digital output, USB 3, and some would argue increasing the sampling rate.